Would it be possible for you to meet a few families that have kids that ar ein the same grade as your daughter? Maybe that might help her situation. I really feel for her. I was transfered to a different school district when I was in the 7th grade. And it was a wealthier district than I had been in. Even the teachers were snobby. It was very hard to find anyone that even wanted to be friends with a stranger. They had their own little "clicks" and nobody new was welcome.
I do not want to scare you, but you might want to keep an extra eye on her. I do not know your daughter and do not want to hurt your feelings by saying this, but it is very important. It could be very easy for your daughter to fall into the wrong group. It almost seems that the bad kids always seem to sneak their way into the lives of a lonley one. It happens so fast, she may not even realize it. If someone shows an interest in being her friend, she might be glad to have a friend and just not realize that they could be big trouble. It is just a scary situation.
With her changing schools like she has had to, I am sure she is pretty smart when it comes to picking new fiends, but just be cautious.
You did not say how long you have been in you knew area. opefully things will get better and she finds some activities that she enjoys, and she will start to meet people.
Good luck and keep us posted on how she does.
Sending hugs her way!