My boyfriend (C) and I have been together for a year and a half now and recently have been talking about me moving in with him and his family (7 y.o. daughter, his elderly disabled mother, and his mentally ill brother).

C and I met in college and he was never secretive about his daughter, when I would come over to study I would hang out with her a little bit before getting to work. At this time when she was 5 ish she was a gem. I wasnt introduced as a romantic partner for her dad until we were sure it would work between C and I, which was about 8 months. He told me he wanted a good mother figure for her and someone to love her, all reasonable requests. And I was able to do that for a while.

In the past 6 or so months she has become a little terror! She is rude, disrespectful, mean to her pets, if she disagrees with you she will hit you (C and I almost broke up because he wasnt doing anything about the hitting) She is constantly trying to sneak her friends up to her dads apartment when no one is up there (to play video games and such). She doesnt listen when you call her to come home and will run out the door as soon as someone comes into the culdesac (they live in town so this is extremely dangerous). She had a temper tantrum because I asked her to say please once. At first I thought it was just me who had problems with her being mean but it is her grandma and uncle as well. Shes only an angel for her dad.

C and I have had so many talks about this and he says that I am jealous of her and that I need to try to get along with her better and I need to stop disciplning her so much (even suggesting I attend parenting classes). The problem I'm having is I am having to help raise her when he is working (swing shift). And when he is home on the weekends he is kinda an absent parent and just hangs out in his apartment, smokes weed, and watches movies. So the daughters grandmother and I are the ones watching her and hanging out with her.

I really want it to work out but have no idea how to proceed with this situation. Any tips?