Stepmother's please help!

So long story kinda short. I'm currently pregnant with my boyfriends baby, he also has a 4 year old from a previous relationship and I have a 8 year old from a previous relationship. Well about 4 months ago his ex showed up and beat me up ( while pregnant ) and she was arrested. We are currently going through court. Well he has 50/50 timeshare. And ever since the fight his daughter is totally different towards me. She cries all the time for no reason, won't talk or even look at me, if I'm in the room she will just look at the ground, she once tried to hit me. She even looks at me rude and out of the corner of her eye when I try to talk to her. When her dad is home she acts like his little princess and he falls for it. She acts out somewhat but he uses the excuse of her age and doesn't punish her. I'm just at a lost. I don't know what to do anymore. I suffer from major depression disorder and anxiety but since pregnancy I'm off meds. I've been fine but I can't handle her anymore. And she says her mommy and meme tell her to be mean to me and my daughter but he doesn't believe it cause of her age and she lies. But every time she talks to her mom or even my boyfriend she tells them I'm mean to her and etc. I just don't know what to do. I'm at a lost. I'm due in less then a month and I watch her while he works but this is an everyday thing she is mean to me and puts me through hell everday. I don't even know what happiness is anymore. Please don't be mean. Just help if you have any advice.