Honestly, I might suggest an abortion in this case (if that fits your views on that topic). It doesn’t sound like she’s in any position to be carrying or raising a kid. IF thats out of the question, you and or someone who holds significant sway over her (parents, close friends, what have you) needs to sit her down and tell her to get help for all these problems. If no one else will do it, you might as well, but try and get help from people who may be closer to her than you.