As cynical as this may sound, the only proper solution for some people is a bullet.  I've seen situation after situation similar to the one you just described and it's pretty fucking pathetic.  These kids get out into the world and find themselves in a place that they never intended to be simply because they didn't know any better and didn't really have anyone to offer them some real guidance.  It's a sad situation, but more often than not you end up with a person who has fallen into the habit of making bad choices and can't be arsed to care about themselves or anyone around them.

It sounds like this girl is making a feeble attempt to convince both herself and you that she's going to change when she truly doesn't have much of an intent to do so.  It's difficult to understand (hell, sometimes it's impossible) but it's something that you have to consider every time you speak with her.  If she isn't serious about changing her life then there's nothing you can say or do to force her to do it.  Being fucked up at parties and continuing to make downright stupid decisions is nothing more than a convenient way to hide from real responsibilities and never take a risk.

If I were you I would back off and let things happen as they do.  Don't let her grow to depend on you as the singular voice of reason in her misguided, self-serving little existence.  It's bad for her to think that she can rely on someone else to fix her problems and it's bad for you to think that there's anything you can do to help.  Have regular conversations with her and back off whenever she wants to bring up any personal issues.

She'll either realize that she's taking an unnecessary risk with her life and try to understand that she's better than that or she'll continue to regress and fuck herself up until it can't be fixed.  Either way, there's nothing you can do to change it and no reason to feel like you ever could.

That's just my standpoint which is based entirely upon my own experiences with people like this.  You do what you feel is right and hopefully things will work out.  All I can really do is wish you luck.

There is no such thing as an addiction...atleast not how addiction is defined... anyways I was a crystal meth/Mariguana addict myself but after having a near death expirience and posting about mah problems here in GW and getting some really good advice,I suddenly couldn't do it anymore... to be honest if someone gave me some free cryz rigth now I would totally do it...but its not like Im going around looking for it anymore.

Your friends will is weak its not your fault..I have a cousin who started doing some weed,went up to needles and now he is insane...he is a self-claimed prophet... 0 _ 0

There is no such thing as an addiction...atleast not how addiction is defined... anyways

yeah let's not explain ourselves on this one or anything