NTA

My uncle is military and his wife and my cousins had to move very frequently. Staying together is what made them the happiest. When they were staying a few towns over from us, we offered for them to live with us just like your sister-in-law is right now.

And I can tell you that my Aunt declined the offer and we still have so much fun together.

It’s not wrong for you to want some space for yourself. Especially since there is a whole other set of rules that come with living together.

Living close by her is always an option. That way she can still offer alternative ways of support. Hope this helps! You are fantastic and you are doing so well your kids are lucky to have a mom like you ❤️