Fire setting and animal cruelty are very concerning. Reactive Attachment Disorder is very troubling. The Macdonald Triad comes to mind. She is a huge liability if she’s setting fires. I think turning her over to state care would be justified at this point. You sent her to therapy, residential treatment, and mental health treatment time after time, which was warranted. She’s headed for violent criminal activity. It’s a long time until 18, so if she commits a violent crime or burns down a house, you could get sued. People could die. Surrendering her is best.
Please keep yourselves safe.