We all tend to jokingly say that “in-laws” are so difficult, which can include mothers-in-law, fathers-in-law, and sisters-in-law (via your brother and from your husband).
However, nothing prepared me for how toxic my sister-in-law (by marriage) could be. After I confided in her about something personal, she phoned my husband to tell him what a terrible wife he’d chosen.
Do you also have a toxic sister-in-law? When you think of your sister-in-law, you instantly want to use descriptive words like “conniving,” “poisonous,” and “underhanded,” right?
It can be incredibly difficult and painful to survive any interactions with someone who is related to your husband or who has married your brother, especially when they are toxic. In the end, you are family and you have to find a way to get along.
Information is power, and here’s everything you need to know about a toxic sister-in-law and how to survive and thrive.
What Is a Toxic Sister-in-Law?
Not all sisters-in-law will necessarily be as directly toxic as mine was, but their toxic behavior may include being bossy, nosy, jealous, competitive, rude, and just plain nasty.
A toxic sister-in-law is usually your relation by marriage (either your marriage or your brother’s), and she is a person whom you would not necessarily want to have in your life if you had a choice.
Your toxic sister-in-law will seem bent on upsetting you, destroying your relationship with your husband (her brother) or your brother (her husband).
No matter what you do, you will always seem to fail at meeting her approval or even being acknowledged as her family member.
If you think a mother-in-law can be bad, a sister-in-law can be worse. You may not believe she has that much power to upset the familial applecart, but she can sow the seeds of destruction if she sets her mind to it.
Your husband’s sister may be toxic because she is secretly jealous that you’ve earned her brother’s love, or she may simply not approve of you as you’re another woman in the family and she’ll feel like she has to compete with you.
Your brother’s wife may feel like you’re a threat to her because you are one step up the social chain in the family to her as the original sister in the family.
She could feel you are being interfering, even though you may genuinely want to get along with her. So she could be acting nastily as a “do unto others before they do unto you” strategy.
Genetically, you are not related to her, and she may instinctively see you as an outsider that needs to be forced out of her “clan.” Her actions may become so predatory that you could end up with a real conflict on your hands.
Signs You Have a Toxic Sister-in-Law
She Doesn’t Respect Your Privacy
A nosy sister-in-law is a toxic one. While it’s natural for your in-laws to want to get to know you as you are new to the family, a toxic sister-in-law will cross boundaries and really dig where she’s not welcome.
Her focus will seem to be on finding out all your sins and shameful past activities.
Instead of keeping your trust, if you do open up and share with her, she will radio out any secrets you confide in her (as I found out). It’s like having a private investigator go through your life with a fine-toothed comb if your sister-in-law is nosy.
Worse still, your husband (or brother) will trust her implicitly, and he will share stuff you don’t want her or the other in-laws to know, which will bring you into conflict with your husband or brother.
Passive Aggression Is Her Way
While she’ll never come all out and say that she dislikes you or that she wants you out of her family, a toxic sister-in-law will find other, less obvious ways of showing her aggression and disapproval. She may say things like:
“You spent quite a lot on that new kitchen.”
“You look lovely in that dress. I could never wear a poor-girl-style dress.”
“You should come around so I can show you how to make my brother’s favorite food.”
She’s Financially Draining
Your sister-in-law may have been the typical “baby sister” to your husband and she’ll still expect him to spoil her financially, despite him now having a family of his own.
She could also insist that you spoil her, and you can see this in little ways, such as going out to dinner with her (at her invitation), only to have her insist you pay for the meal.
When you and your husband go on holiday, she will try to wangle it so she can come with you, at your expense, of course.
She Twists Your Spouse/Brother’s Mind
When your husband or brother has spent time with her, you can see them look at you differently. She seems to find ways to poison their mind against you.
Your husband will begin doubting you when he’s visited her, or your brother will start spending less and less time with you and your folks since marrying (more so than is normal).
She Wants to Decide for You
Shopping with your sister-in-law is a nightmare. She will try to make your decisions for you.
Instead of respecting your taste and likes, she will try to convince you to do things her way. Her manner will suggest that she knows best, from what to wear and cook to how to raise your kids.
You especially see this in older sisters-in-law, as they will try to step into the shoes of your older (and therefore wiser) sister, giving advice (and expecting it to be taken as law) without asking and insisting they know best.
Her Statements and Comments Are Negative
Your toxic sister-in-law will be openly critical of you, and her comments will always tear down your authority and right to decide for yourself. I know a couple of my toxic sister-in-law’s comments included:
“You can’t cook that for the kids.”
“That’s not how you clean an oven; let me show you how.”
“You’re being too critical of your husband/my brother, and you should know your place.”
Ultimately, it can be really challenging to handle a toxic sister-in-law, and you may be at your wit's end by now. But there are a few things you can do.
7 Steps to Handle Your Toxic Sister-in-Law (That Doesn’t Involve Poison)
No, poisoning her isn’t on the menu, even though you may have looked at the shelf of rat poisons at the local supermarket with a feeling of “if only.” Your toxic sister-in-law is still your family.
You may wish your husband had been an only child or that your brother had been gay or a monk instead, but you are stuck with this sister-in-law, and you have to make the best of it.
Here are a few ways to handle your toxic sister-in-law, create some boundaries, and co-exist more peacefully.
1. Keep Secrets in-House
If your sister-in-law tends to gossip or talk about you behind your back, don’t trust her again. Information is power to her, so don’t share any.
This includes sharing by your husband or brother or your children. Ensure these people know not to discuss you, your past, or any current events (affecting you) with her.
Your husband or brother needs to understand you are a private person, and while your sister-in-law is family, you are not a topic for discussion.
Help them understand that if they won’t say something to her in front of you, they shouldn’t discuss it behind your back either.
While it may be hard to come out and tell them you don’t trust your toxic sister in law, you can find other ways to get the message across that you don’t want your personal details shared with her.
As the saying goes: don’t talk out of the bedroom. And, you can teach your husband or brother not to talk about your life either.
2. Ignore Her Comments or Face These Head-On
If your sister-in-law is toxic in what she says, you should not agonize over her words. Instead, decide whether the comments are tiny insults that you can ignore or if they are challenges to your authority.
If you feel the comments aren’t insulting enough to react to, then ignore them.
However, if you feel her comments are really offensive, then you should find your inner quiet and face her down. Your goal shouldn’t be to have a raging battle or screaming show-down with her.
Instead, remain calm, and tell her in an adult manner that her words are unfair and unwelcome, and that you won’t tolerate being spoken to in such a manner.
3. Handle Her Interference and Negative Reviews
For a sister-in-law who is very interfering or who constantly criticizes you, it’s a good idea to calmly discuss this behavior with your significant other or your brother (if she’s his wife). Take care not to discuss your sister-in-law as a person.
There is no way you will convince others to get her out of their lives (or yours), so aim to lay boundaries instead.
Explain to your brother or your husband that your sister-in-law is interfering in your business, challenging your authority as a woman, wife, and mother (if there are kids) and that you won’t tolerate that kind of behavior.
Remain calm so you don’t come across as being temperamental or catty. You are an adult here, and what you are asking for (to be respected and treated with dignity) is not something unreasonable.
If your brother or husband tells you to just accept your sister-in-law or that “that’s just how she is, and she doesn’t mean anything by it,” you will have to lay down the law a little more forcefully.
Indicate that such behavior wouldn’t be accepted by them if they were in your shoes, so you won’t accept it either, and then minimize your contact with your sister-in-law.
4. Deal With Nosy Comments
You probably hate it when your toxic sister-in-law pokes her nose into your business. She may ask personal things like when you and your husband are having children, why you’re not earning more, or when you are going to move into a bigger house (suggesting yours is too small).
Handling nosy comments is stressful, especially if she is trying to provoke you.
Deal with these comments by stone-walling her. Don’t respond, change the topic, or tell her up front that this is a personal subject that you’re not going to discuss with her. Don’t let her manipulate you into responding when you don’t want to.
Be polite, but be firm, and don’t let her bully you into answering uncomfortable questions.
5. Critical Comparisons
“You are always sleeping during the day; when do you even clean your home?” My sister-in-law asked one day when we were having tea with a group of friends.
Her insinuation was that I was not a worthy woman because I wasn’t up at 6 a.m., cleaning house and baking up a storm.
However, while she was a homemaker (aka housewife), I worked long hours as a freelance writer, and mornings were often the only time I got any sleep.
Handling this kind of criticism, especially when it’s delivered in public (my folks were present), can be a challenge.
My advice: Tell your sister-in-law (in a calm manner) that you and she lead different lives, so you have to do what works for you.
You can also tell her that you respect her for her life decisions and how she handles her pressures—leaving it hanging that you expect her to respect yours.
6. Being Pushed Aside
Your sister-in-law may also push you aside, leaving you out of family discussions and activities, forgetting you are also family. This is painful!
Handling this may require that you speak up for yourself or simply show up, even if you weren’t invited.
You have to carve out space for yourself in your new family if that’s what your husband wants. Find ways to participate, and even if you suffer criticism for it, don’t back down.
Remember: Always keep yourself composed and dignified. That way, she can never find fault with you.
7. Handling Accusations
Having your sister-in-law accuse you of things can be even worse. I’ve had my toxic gem-of-a-sister-in-law accuse me of stealing her watch after a Christmas at their home.
Of course, I knew nothing about the missing item, and it turned out that it had fallen behind the dresser in her room.
While I had every right to be absolutely enraged, I kept my calm and told her that mistakes happen so easily. I told her it was a pretty watch, and that I was so pleased she found it.
Where she had expected to provoke me into showing my ugly side, I kept my cool, and I managed to flop her plan. She ended up looking like the nasty dragon that she is, while I maintained my composure and earned the admiration of the family.
To Tell or Not to Tell
When your sister-in-law is a toxic person, it’s difficult to know whether you should tell your husband or your brother (if she’s his wife). In most instances, you will look jealous and petty if you tell how toxic she is or how uncomfortable she makes you.
Ultimately, it’s a complex situation, and you don’t always have the option of just avoiding her or never having any contact with her. After all, you and she are family now. So, when deciding whether you should tell or not tell, here are some considerations:
If you do tell people how toxic your sister-in-law is, you may end up regretting it if the reward for speaking up doesn’t match the risk of having your family ostracize you.
It’s up to you to act with integrity, keep her at a distance, and make the best of situations that could break you down if you don’t stand up for yourself.
Final Thoughts on Toxic Sister in Law
Having a toxic sister-in-law to deal with is any woman’s worst nightmare. She can really complicate your life since she is now part of your family.
However, with a calm approach, you can win the day, stand firm, and earn the respect of your family for handling such an obviously challenging situation so well.
Remember: She’s also afraid of you, she feels intimidated, and she’s acting on a primitive instinct to try and stay above you in the pecking order—you are an evolved being, and you can handle the situation with empathy and resilience.
Learn more about compassion and empathy with these 105 quotes about empathy.
And if you're looking for more articles about dealing with toxic people, be sure to check out these blog posts:
- 11 Steps for Going No Contact with Your Toxic Parents
- 15 Warnings Signs You Have a Toxic Girlfriend
- 17 Sad Signs Your Daughter Has Become A Toxic Person
Finally, if you want to identify YOUR personality type, then take one of these 11 personality tests to better understand what makes you tick.
