A mother's dissatisfaction with her step-sister puts her daughter in a predicament.

My mother is very critical of my brother's wife, to the point where she blames my brother's “mistakes” (not getting a better job, not taking good care of his health, etc.) on my sister-in-law. It has gotten even worse now that I have grandchildren. My mother constantly criticizes how my sister-in-law is raising the children. The children are sweet and adore their grandparents.

My mother sometimes has critical opinions about my sister-in-law and brother-in-law, but most of the time I'm her listener.

I have a very good relationship with my sister-in-law, and when my mother gets abusive, I cover her up. I told my mother how lucky we are to have such wonderful grandchildren and pointed out that my brother is an adult who makes his own decisions. This only causes quarrels between my mother and me.

When I finally told my mom how much it hurt to hear people say things like this about my sister-in-law, she said I needed to take my frustrations out on someone. I want to be there for my mom, but I don't like being put in that position. How do I navigate this?

From the therapist: The simple answer to your question is that you can move past this by not participating in these conversations. But I think you already know this. What you may not realize is that you are not “put in this position” as a supportive daughter, a protective sister-in-law, and an unwilling best friend. Since you chose it, it's worth considering why you took the job you didn't want and what makes it difficult to leave.

Usually when we find ourselves repeating uncomfortable family patterns, it's because they reflect familiar roles from our childhood. It sounds like you are struggling with “entanglement,” a relationship pattern in which boundaries between family members become blurred or non-existent.

Think of intertwining like two trees that have grown so close that their branches intertwine. Although this may seem like intimacy, it actually inhibits the healthy growth of either tree. In your case, your mother's emotions and frustrations are so intertwined with your own emotional life that it is difficult to distinguish where her emotions end and yours begin.

You said that even though you were hurt by this conversation, you wanted to “be there” for your mother. Many adult children who cannot say no to their parents have grown up acting as their parents' emotional support system or absorbing their parents' emotions, even at the expense of themselves. When you told your mother how much her outlet hurt you, she reacted by claiming that you needed to “vent your frustrations” rather than acknowledging your feelings. Her reaction reveals something important. She sees you as a vessel for her emotions to spill out of, rather than as someone with valid emotions of your own. And yet, even though you're hurt, you're more concerned about her feelings than your own.

You're asking how to get through this situation, but I think the deeper question is how can I learn to take care of my own emotional needs?

We can start by reframing what it means to make reasonable demands. This is essentially setting boundaries. Boundaries aren't about pushing someone away. Instead, it's about bidding for connections. It's, “I want to feel good when I get closer to you, but when you do X, I want to avoid you.” Help me get closer. ”

Establishing boundaries consists of three steps.

State the problem and the desire to be closer (what makes it possible): “Mom, I love you and want to support you, but about my sister-in-law… These conversations put me in an impossible position and I want to help you avoid talking to you. I know that's not what either of us want. I'm happy to talk about other things together, but to keep our relationship strong, this topic needs to be off-limits. ”

Set boundaries (what to do): “If you're struggling with their choices, I'd be happy to help you find a therapist to help you deal with those feelings.” But if you bring these complaints up to me, I can end the conversation and talk about it another time.''

Maintain boundaries (do what you say): Boundaries are not about what the other person will or won't do. Boundaries are contracts you make with yourself. If your mom tells you to stop the conversation when she brings up your sister-in-law, you need to hold those boundaries every time. If you only end the conversation 90% of the time, why would the other person honor your request when you yourself can't honor it 10% of the time? It may sound like. “Mom, I don't feel comfortable talking about my sister-in-law, so I'm going to stop the conversation.'' I love you, and we'll talk later. ”

If you start to feel guilty, remember that just because someone sends you a guilty message doesn't mean you have to accept their delivery. Remember that when you become an outlet for your mother's criticism of your sister-in-law, you are participating in a cycle that strains loyalty and causes personal pain. And remember that being a good daughter means setting boundaries that encourage growth in your parents, rather than enabling patterns that undermine family relationships.

Why not ask a therapist? If you have any questions, please email askthetherapist@nytimes.com. By submitting a query, you agree to our reader submission terms. This column is not a substitute for professional medical advice.