RD
(((hugs)))
I don't know what advice to give.
If it were my child, no way would I let her live with a parent who let her run amuk, not if there was anyway I could stop it from happening.
I know you trust the boyfriend's parents.......But a word of caution.......she should not be spending 12 hrs a day with a boyfriend and his family. Nor would I rely on the parents to provide adequate supervision, most especially for long periods of time. I made that mistake and wound up with a pregnant teen because the boyfriend's parents would just up and leave them in the house alone for periods of time.
Your easy child is balking at home rules because she gets a free ride at daddy's house pure and simple. Odds are once daddy has an out of control teen on his hands (and he will if he gets custody) he'll be pushing her off onto you.
Hoovers. I'm sorry. Wish I knew some wisdom to help.
Hugs
