I need advice😔

I'm 17 & I need advice on what to do!😔 I have a really close friend that's addicted to drugs; crystal meth, marijuana, different type of pills & alcohol she's been on all of those ever since she was 14(she's also 17 now)... She has been to rehab & has gotten every help she needs she's currently not in school & doesn't have a job because of this problem. Her mom doesn't do anything about it! She totally gave up on her because she has other kids to worry about too.. The last time I saw her was probably a month & a half ago well we hanged out today & I noticed that she lost so much weight & she told me she has been diagnosed with anorexia💔 I feel like I'm slowly loosing her I know one day her body won't handle anymore drug & will just shut down on her I'm not ready for that! I'm currently 7 months pregnant & I feel like I need to do something about this she's getting no help & her bf is a drug dealer what should I do?! I'm so heartbroken & can't stop thinking about her I've tried talking to her over a thousand times & she just won't understand!!😪 I have a feeling that time is coming up!😣