About emancipation?

hey well...i am trying to help my sister get emancipated. she is 16 and will be 17 on june 20th. Some things are going wrong at the hosue that are getting way out of hand. my mom has a mental illness and she is not taking her medicine for it. She is abusing my sister, dragging her by her hair...slapping her so hard that she falls off the chair and it leaves welts...the list goes on...i am 20 years old and no one is helping me in this matter of emancipation. I would like her to come live with me. I have an extra bedroom that she can stay in and more than enought money to help her with whatever she needs help with. She has a job and she can pay for her own things as well. my dad was all for the idea but just because of some online thing that said it would be difficult he doesnt want to help so i am on my own. Can i do this and what things must i do to make this go through so we can get her out of there....anyone can you please help me!