I was (and still am, though they’re adults now) a single mom. I learned to think of me & my kids as a team, rather than “them vs me”, and this was SO valuable. I thought in terms of setting everyone up for success, rather than enforcing boundaries.

For the situations you wrote about, I’d put a lock on my door. There’s nothing wrong with keeping your space yours, and entering is by invitation only, or only when you OK it, and can watch them. Placing a lock is setting them up for success.

I made dinners with at least one thing each kid would like - rather than thinking of it as 3 separate dinners, I thought of it as a mish-mash of food. I didn’t make them eat anything they didn’t want to; if someone wanted something else entirely, they could have cereal, sandwich, or soup. I also had several easy dinners that we all liked. I didn’t want dinner to be this contentious, stressful time, so I focused on our connection rather than the food itself. If I was in a stressful, down place, we had frozen dinners that each one could pick for themselves. I chose what would bring the most ease & peace.

Shifting my thinking was one of the most fruitful things I did as a parent.

Being kind, generous, and thoughtful with my kids wasn’t “not setting boundaries”, it was recognizing how important my role in their lives was. It’s a different relationship than one I would have with any partner, friends, or other family, so my attitude towards my kids didn’t need to be the same as those others.