How to get my friend to stop drinking?

Ok first off, im a christian. My friend is in grade 10, like me. We met a few times at school then were talking on facebook. She's really cute, and she has a slightly scene look. We met up sometimes at school and I found out she is REALLY attracted to me. We went trick or treating together (no, you're never too old lol) and I'm a really caring and sympathetic person, so I got her talking about her past. She used to be a really serious Christian, like she would read the bible all the time and stuff. But she somewhat fell away, she believes in God and stuff still but she's not really a Christian. And it's almost hard to blame her. She told me of her past, and she had a extremely abusive childhood and she's now living with terrible foster parents. She's somewhat suicidal because since she feels she has no reason to be living anymore. But she is extremely kind and caring to everyone because she knows what its like to be disliked and abused. She has funny mood swings too. She gets drunk a lot. she admitted she was pressured into sleeping with her former boyfriend once (when she didn't want to). She's a very messed up girl, she even says so. But somehow, i wasn't repulsed at all. I just feel really sorry for her. She's incredibly cute in looks, her voice, and personality, and she's not slutty at all. After she had told me everything she said 'do you feel different now? Like I told you a lot about my past... I'm a very messed up girl'. And I told her that I didn't like her any less, I just feel really sorry for her. She was amazed at how nice and everything I was and admitted that she liked me, rather than just being attracted to me, which she was before because she 'didnt want to get hurt again'. I really like her, and want to help her. I've done it before with depressed people. I've actually done really well at it. But I need to know: how can I get her to stop drinking? Please help!