Hi Tacoma,
I'm also new here and have a son with some terrible problems. There is a 2 year old child tied up in our partiular saga, his child, who now lives with me.
I apologise for being cynical, but please ensure your daughter has some form of birth control that does not rely on her taking a tablet, because if she fell pregnant, your nightmare will have only just begun. Little children do not need parents like thses kids.
I'm sorry you are going through this, and have some understanding of how you must feel.
I think a psychiatrist may be the best option for you. Ask around, some are more interested in youth and their problems. a psychologist will only give therapy, not a diagnosis. If it's abehavioural disoredr, you may never really have a diagnosis. My son is too clever for a psychiatrist, so continues on his merry destructive way.
Goosie