R.D.
It sounds to me as though her teacher(s) or principal have a problem themselves. How can she do so well in another school, now back to old one and this!! It sure doesn't make sense to me.
When my son was in grade 7 he had this teacher that used to call me every chance she got. He was a trouble maker, he wouldn't listen and on and on it went. Finally she caught me in a bad mood and I simply said to her "you don't like Donny" do you? She said I didn't say that. I said "no" because you can't. I went on to say to her that if she didn't like him, he in turn would not like her, he would sense this. After this she quit calling. The following year he got the Highest Achievement Award. So there is one teacher against the other. I would go into the school, "ask permission" to sit in on the class and see whats' going on. I don't know if your year end ends in June or not as ours' does, if not I would definetly go directly to the school.
Have her checked by a Specialist (I don't think, you need to worry) just to satisfy those who think they know it all. If you are a young parent as well, you will find that they will try and manipulate you into something. Don't fall for their games, check it out yourself.
I wish you the best of luck, been there myself!!