There's not much more I can add. I am so sorry...for you and your daughter, and your gf. As far as where she is at...if this is where she is 10 months into it, and she has no desire to seek help, be ready. It is progressive, and it gets ugly.
I discovered my husband's issue. I chose to put my head in the sand early on thinking it couldn't be that bad. I had no clue. Just as the books tell you, it progresses, if it is not dealt with, it only gets worse. Those of us living with an addict can't do a darn thing about it. It is a horrible life to live and if I only knew what I know now, I would have taken a HARD, HARD STAND early on. My life would be much different today. If my husband would have recovered, we would be living the life we were meant to. If not, than I would be living the life I was meant to without him in it. I have lost years...precious years that can never be replaced. It is not a life I would wish on anyone, and when you stay and try to wait it out, hope it away, it just sucks the life right out of you.
It is too bad she can't see the forest for the trees right now. Drugs are against the law...doing them once is too much.
Take care...