i've danced with that devil as well... there's no way your friend is going to get clean unless she really wants it, and i mean really really wants it like nothing else.. she's gotta go after getting clean like she went after the dope for reals.. you can talk to her till you're blue in the face and unless she wants to get clean, your just wasting your time bro.. it's still super hard to get clean from dope even if you really want it tbh.. thank god for drugs like methadone and subutex, suboxene, and i've been clean for ten years this last may...
she's going to need to change everything in her life if she wants to stand any chance of getting and staying clean for any period of time..i had to walk away from life long friendships, places i've lived and hung out at in order to do it.. i've also stopped drinking any alcohol for the most part as it lowers in inhibition and makes relapsing a much more likely thing..
i don't know what else to say.. sit her down and ask her if she wants to get clean..if she says yes, and sounds like she really wants it, help get her to a methadone clinic and or a rehab..
if she says no, tell her that you love her as a friend, but you simply won't sit back and watch her go down this self destructive road anymore.. let her know that if she ever does decide to get clean, you'll be there for her, but up till that time, forget about her.. it will be the easiest and best thing that you can do for both of you..
goodluck to you and your friend..