I had a friend who was the same when I was at school.all these years later I see him around,he's treated everyone this way because he thinks he was better than everyone else and just takes a free ride of people when he can. She sounds the same. My advice..sit her Down with your other friends and let her know what she's doing isn't very nice and you won't stand for it and that if she's wiling to make a better approach too friendship with you then the door is open.

Kia Ora