I am very sorry about what you are going through. The posts on this thread have hit me in a way I did not expect. You all are talking about your children. My oldest is 17, and right now it seems he will never consider drug usage ever. My daughter is 15, and I have noticed her sneaking alcohol, and it worries me. The others are younger, so I can only hope to figure out my part in this before I send them all down the wrong road.
The other part is the comment about a functioning addict. That is what my AH always calls himself, and he sure keeps me in fear of him being gone, because without his financial support, my children and I would have no way to support ourselves. There are just so many pieces to the puzzle, it often seems it will never come together.
I am hoping and praying that your AD will desire to get the help she needs.