C.,
I am going to start by saying I was one of those bad girls! I didn't start quite this young but I was an awful child!!!
I hate to say this... by putting her in an alternative school you could be setting her up to learn more negative behaviors from her peers. I would say that 75% of the kids do not do well, in the long run... atleast from my observations and by looking up names of kids I went to school with on the Illinois State Inmate Search and also talking to some of them. I was one of the lucky few who grew up and grew out of this stage.
My son was also a "bad boy" I considered placing him in alternative schools but decided against it based upon my experience. He did get services through his reg. schools though and while it helped from 5th grade to the beginning of HS, once he hit HS all hell broke loose!We changed schools even and because of the label he carried with him he was treated as a 1st grader would and his education suffered. He was given picture books to read and basically no further education. VERY VERY long story!!! Be very careful to not let your daughter get labeled as a "bad girl", especially so young!
My sons school (5-8th grade) set it up with him that if he felt he was going to melt down he could go up to the teacher and request to see the counseler. She helped him to recognize his behaviors and what was appropriate and when he needed help. She was truly amazing!!! She really worked well with him and made him successful until HS. I sure wish they could have brought her with him there!
Consider other resources... counseling, interventions, church etc.... There is plenty of them out there for her. Start the counseling before school starts so maybe she can begin in the new school with a fresh start!!!! Remember that she is also going through a very tough time moving in with you and having to compete for attention even if it is negative attention she is seeking. Granted, I do not know your whole story so I am jumping to conclusions but... well you know how it goes on here!
I just would hate to see such a young girl who is obviously in need of help to be labeled and not be able to get rid of it! Remember you will have to do IEPs and many meetings with the schools. I would try the counseling first and see if they can do something to avoid even special ed (behavior) classes at school. If she does need special classes in school make sure she is not put in a LD class as her education will suffer as my sons did. Try to exhaust all other possibilities first.
I wish you lots of luck and many blessings through these tough times you are facing!