I am sorry, I feel your pain, however, IMHO you really need to work on you, are you going to Alanon meetings yet? If you do not help yourself first, no one will get healthy.
You can kidnap her, lock her in her bedroom and she will figure a way out, she will not seek recovery until she is ready. Attempting to move her back in your home is not the answer...her friend is a young girl like Amber, she really is not in a position to understand what will or will not work. Addiction is a complex disease, there is no easy fix.
Have you been reading others posts on this board? That includes the F & F of Substance Abusers? What about the stickeys? Addiction is Addiction, and now your daughter is doing drugs of some kind, so what is posted on the Substance Abusers Forum applies to your daughter.
I want to support you. However, you post, I respond, and then immediately...poof, you are gone, a month or so later when there is another crisis you post again.
I understand that it is your choice, and, I take no exception to that. However, one thing I do know is that recovery from addiction and/or codependency requires follow through, successful recovery is not a hit or miss program. It requires total dedication.
Just my two cents, take what you want and leave the rest.