P-Nut, LM sounds very disturbed. I adopted a child who was attachment disordered and he did everything she did (although he had no chance to b urn anything down), but he did kill a few dogs. He also abused his two younger adopted siblings and I'd worry about that with LM too. Once they get that disturbed and unattached with younger siblings, it becomes a danger and treatment is difficult, if not impossible.
I did not read any other answers you got or finish reading your post beyond LM, but I think she needs to live elsewhere. She has all the signs of a sociopathic child (Reactive Attachment Disorder (RAD) is just that). You can't know all that she has done because the other kids will be afraid of her. This is what happened to us. We found out what our kid did, AFTER he was gone for several months.
We didn't think our child had any chance to do anything either and we thought our younger kids would certainly tell us if anyone tried to touch them "bad" because we had repeatedly talked to them about it, but both were more afraid of him and believed we couldn't help them...that he would just kill us, as he threatened to do.
Have you considered putting an alarm on her bedroom at night so that she can't get out without your knowing it? She may prowl in other rooms at night. Also...as hard as it is...I wouldn't let her be alone with any of t he other kids. She'd have to be in sight at all times, even outdoors.
We hid everything too, just because we had foster kids (we had no idea THIS kid was a threat), but apparently he'd go into stores and easily steal lighters, knives, and other dangerous items without getting caught. As soon as we found out he had actually been the one who had killed our dog and then that he had sexually abused my two younger kids, that was his last day in our house. We called DCFS and told them to take him.
What you do is your choice. You may look around to see if she can live in an Residential Treatment Center (RTC). You probably do not know what she has been doing to everyone. It is a big red flag that she has killed an animal...and there are other red flags for her. Hugs!!!! and good luck. I feel so badly for your family and your poor kids. And I don't think bio. dad should EVER get his kids, but I know how hard it is to prove somebody is unfit...Back to our son we adopted who is no longer with us, he also had language issues and learning problems...I wonder if that is part of arrested development due to abuse. A lot of these abused kids have them, although plenty of not abused kids do too.
I wish you the best. You have some hard choices to make.
