It sounds like the arrangement and the relationship for the most part is working well, but meals are the issue. As PPs have suggested, take the meals out of the equation. Everyone is on their own for meals and dishes, more like roommates. Get together for takeout if that works more smoothly. That way the personal hurt of something she made for her daughter being criticized is taken out of the equation. And daughter does more adulting.

Anonymous wrote:Why is this 27 year old failure to launch daughter living with her?

A PP here. Lots of families have adult kids stay with them until they are older. It’s not necessarily failure to launch and nothing OP even implies this is a failure to launch situation.

Why is this 27 year old failure to launch daughter living with her?

Her daughter is really kind in general trust me but she has these disrespectful moments and it makes me so mad. Its not okay. You eat whats served thats it.

Your cousin is 27. At 27, you don’t need to eat what’s served. Not ok to be disrespectful but not ok to be treated like a kid either. They need to come to some understanding about meals. I have young adult kids still at home. What works for us is the let everyone know what’s for dinner and what time we’re eating (varies depending on whether we go to the gym). Then they let us know if they’re planning to eat with us. If they’re not home, we don’t plan for them unless they text and let us know they want to eat with us.

OP, as a non-mom, I don't think your sister will give you the "standing" to see you as an advisor.

I don't think there is anything you can do here to help. When an adult child comes to live at home, (most of the time) it throws both parent and child back to the patterns of last high school year, so the kid does "infantalize" down--and so does the parent. It's really hard to break the patterns that involve both dealing with a parent AND being in the same territory as you were as a child.

The classic is your 40 y.o. totally funcitional kid comes home for Thanksgiving, and suddenly you are doing their laundry and dishes. Some parents have noticed that when they (the parents) move to a new house, it's easier to start up with new behaviors when an adult kid comes to visit.

But an adult kid in the house of their youth, with their parent, and LIVING there, not visiting? It's an environment that is not set up for the kid to engage in "adulting" behavior.

So my advice is to just be a kind ear for your sister.

So you have seen your aunt in tears over the daughter’s comments? Your only question to your aunt should be, “Why do you accept this behavior?” If your aunt doesn’t complain to you, stay out of it.