Problematic Student
 

Hi, everyone!
First of all let me thank you for a fantastic web-site and this forum! I got rid of million of my hang-ups, connected with teaching! It's always great to know, you are not alone!
Here's a problem which has appeared in my class recently.. Maybe you have already faced that,and possibly you could give me some good advice on it!
I teach children (13 y.o).. In September there appeared a new girl in my class. She came together with 4 new students, and somehow she was the one,who actually didn't manage to become a part of this class... Children don't like her, and can't miss a chance to make fun of her...This class is very friendly, in fact, and I never saw them act like that before...All this made me quite sad, because I try to maintain the atmophere of respect and friendship at my lessons...
Then I realized why they had been behaving this way.. The girl is quite bully herself, and I notice that it is she who actually starts the quarrel! My private conversation with her after class shows that her behaviour is of "The best defense is a good offense" type..
How can I help this child integrate into our "small family",and get rid of her complexes? Maybe somebody had "difficult students" in their classrooms? What are your suggestions?
Thanks