Some sort of emancipation...?

Hello. I am going to turn 18 in less than a year and I was wondering if there was some way I could take my little 9 year old sister when I leave my house from my dad. I will be moving out with my baby's dad and my baby. I really don't know if I need to go to a lawyer or if it something I could do on my own going to court. The reason I want to take her is because I don't think she'll be safe with my dad. He uses verbal abuse on us both, and he kicked me out various times when I was 12,and he once bit her on the breast area. She told her school and they called DCFS and everything was okay while the social workers were coming over but he has returned to his old ways of drinking and I also believe drugs. I am seriously scared for her. She also recently told me he stuck his finger down her throat and like wiggled it. I think that's kind of perverted and Im just scared and creeped out what he'll do once I leave. So, what are the steps i would need to take to be able to take her with me?