How do I help my pregnant girlfriend with something like this

My girlfriend is 16, and she's a month pregnant (no hate, I've been with her 4 years and I don't plan on leaving her ever) She's too younge to leave home, she has about 5 months until her 17th birthday then she can leave. She won't call CPS either. Her mom and brother are complete slobs, never clean and never offer her help when she's deep cleaning her house every week. They have a dog and 2 cats, all of which are infested with fleas and they have a serious roach infestation. She's begged them to clean but they never do. They know that she's pregnant, and they smoke in the house, around her, in the car and even in her own room. She's an extreme germaphobe and extremely OCD. She has panic attacks and break down over the sight of bugs, specially roaches, bed bugs and fleas. On a normal occasion I can get her to calm down, and just think about it but sometimes I can't and she completely snaps. About 3 months ago she was arrested for Assault and Battery because she had spent hours cleaning her house, top to bottom even cleaned the damn ceiling for her brother to come home high, cook a big was meal and leave a giant mess. When she asked him to clean it, he said "why don't you do it you're the clean freak" then she fought him.

She was getting better after that, and she only has a couple months left but I don't know what could happen in those months. I want to help her but I'm not exactly sure how, she used to smoke a little bit of weed and calm down but now that she's pregnant she refuses and I wouldn't let her even if she wanted to. I love her to death, but I have no idea how to help her. I don't mind going over there to help her clean but she works a lot and isn't home to keep it clean. Her mom and brother don't work at all and just sleep all day