Lots of good advice here if you're able to keep open to it.
I would just mention about the personal care problems, things can be more complicated than they seem. For example that children cannot control much in their lives, but body control is there's, and slowly becoming more and more theirs as they grow up. Fights about bodies and appearance are likely about control and body autonomy, not just tangled hair!
Personal care is also about self esteem and self worth. And wanting to take care of yourself, or feeling like you are not worth it. Or that making yourself dirty or unattractive is a defense against the world.
Btw, I'm trying to learn how to take care of myself now, as a fully grown adult. Because of a very disturbed upbringing. Not making a comparison between you and my mother, as you don't deserve the vitriol (!), but an example of how personal care is a complex thing... For me it was about 1. my worth as a human being (or rather lack of), 2. privacy and bodily autonomy, and 3 a taking back of control in whatever way I could.
I also think now it was a way of breaking through all the family veneer of normality, a way to silently scream out my fear and desperation to see if anyone out there would help. Sadly they didn't, but I try and help myself now as an adult.
Your dd's situation doesn't seem like mine growing up, but I wonder if she's tapping into any of the same needs and concerns, albeit for different reasons?
My mother was (is) a deeply disturbed and horrible woman, who refused to give me any sense of self, identity, and my needs completely denied. I was the family scapegoat and was defined by my role in others lives vs as an actual person.
I internalized that message, from a very young age. I was nothing and no one, and I was worthless. In direct contrast to everyone else in the family. So how do you care for yourself when you know you are a revolting piece of scum with no rights to be considered equal to any other human being?
She also had no boundaries and made me very very uncomfortable with her refusing me any privacy or basic boundaries. By the time I was 10 I was avoiding anything to do with the bathroom or toilet as I was so effected by the enforced lack of privacy. I've never told anyone this but I used to pee in my room and sneak out in the early hours to pour it down the toilet. Just so I could get some privacy. I had to endure the forced hair washing and the painful hair dryer wielding, but in every way I could I pushed away any sense of my body.
Needless to say, my mother didn't have any clue about the results of her behavior. And wouldn't recognize any of this as a description of my life. Which is why I don't think you are similar to her, as she certainly wouldn't have sought out any advice or help in taking a different approach or perspective.
Good luck.