Hi Dad!
Huge hugs, I think it's extremly difficult in dealing with addiction and teenagers, very difficult, because most don't have the capacity to believe they need help. Your fighting an uphill battle if she's not willing, going to just be blunt. You can keep making her go to the addictions counselor which I think is your best bet. Set some firm ground rules, and don't let her rule the roost! She may leave for longer periods of time, she may runaway completly, but it's not about you, and don't blame yourself okay?
Her brain is slugged with chemicals distorting her thinking, she has absolutly NO clue, she's harming herself, she's having fun as she see's it. It's tough, real tough, and she won't get it until she's either more mature, or ready to seek help. I know it's not what you wanted to hear, but it's pretty much the truth. I was her once.
You however can go to an Alanon or Naranon meeting to get some coping skills, visit our forums here on those topics.
I will pray for her and you and your family