I’m sorry you’ve gone through all this, OP. I would say that your mum in a lot of ways sounds similar to mine. Maybe to different extremes.
In my case, my mum grew up in a home where she had to be a people pleaser, making everyone happy, in order to survive because she had a brother who is by all accounts a narcissist and probably a sociopath. I don’t mean a narcissist in the pop psychology, everyone is a narcissist sort of way, but I mean truly had narcissistic personality disorder and probably a few other things.
As a result, her solution to getting through life was to make everyone happy, never say no, have no boundaries or rules. If I wanted a puppy, I got a puppy. If I didn’t want to go to school, I didn’t go to school. If I wanted to go live with a random 21 year old guy I met at 15, she’d pack my stuff and drop me off. Like you I missed a lot of school. She just stopped taking me. For 2 years, I ate ice cream in bed for breakfast because I must have said I wanted ice cream for breakfast and she used to bring me a bowl when she came to wake me up.
I was actually a very good student and did well in school (once I got back into it), but my teenage years were weird, a lot of permissiveness that seems very strange now that I’m a parent. If she’d had a man in a bus in Morocco to drop me off to, she absolutely would have.
Late in life, she met and married a man who has a history of child sex offences. She’s perfect for him, because she has no normal boundaries. Everything is fine and normal because she just wants him to be happy and pleased with her. We are NC, because obviously I would never allow someone like that around my children or myself.
What I’ve come to understand is that she is someone who is just quite emotionally immature, gets her sense of self worth from how much she feels like she is making others happy, making happy means never disagreeing or saying no. So there was just no structure to my life growing up.
Maybe like you, I became quite hyper independent. I could take care of myself. I didn’t need anyone. I survived. I learned that people around me couldn’t be depended on, so I stopped ever depending on anyone. I’ve worked on that a bit as an adult and I do depend on a select few now. But everything you say sounds very familiar to me in a lot of ways.
So no, it’s not normal or acceptable. It was actually only when I told the stories above in therapy that I heard them for the first time from someone else’s perspective and realised how bonkers some of my childhood was. Healthy boundaries have been key for me and finding ways of healing that involve depending on family I’ve created, not the one I was lumped with by chance, have helped.
As for going NC/LC, only you can answer that. It was pretty easy for me, because my family is literally unsafe for my children. But it also was about a feeling of what I needed to move on and live my life. If my mum had been a boyfriend, I would have broken up with her well before I did. I eventually accepted that I couldn’t live with that pain and also live a happy full life. I have zero regrets about being NC.