My BF was molested. How can I help her?

I think my best friend was molested by her step dad but I don’t know what to do or how to help her. My friend and got pretty wasted last weekend and my friend got really upset and started doing tequila shots. I had to like practically fight the bottle away from her by the end. She was so drunk and she was passing out and then she ended up crying and cursing and she kind of told me that she lost her virginity to her step dad a couple of years ago. I am so totally worried about her. She still lives with him and her mom and I don’t know what to do. I brought it up right away the next day and said she could come live with me and my mom and it was no problem at all but she pretended like she didn’t know what I was talking about and then she got really mad and said that she never wanted to hear anything about it from me ever again and that she would never forgive me if I told anyone about it. And since then it’s like she has been avoiding any time alone with just me so I can’t bring it up again. I don’t know what to do. She is like a sister to me but I don’t know how to help her. Should I respect her wishes and not tell anyone, or is she just in some sort of denial or something? If I do decide to try to get her some help. Who should I tell and what would they do. The whole thing is a huge mess and I can’t sleep at night knowing what she might be going through on her own just a few doors down the street.