This girl is new, and in her new school there is a lot of gossip, everyone had already gossiped that she was new. She had interacted with other students but they treated her badly, so she entered the classroom and went to you

"Wait, you want to be my friend? Why doesn't everyone here at school like me? Because I'm new?"

You tell her to take revenge on them, and you advise her to listen to secret information from them and spread what she has heard to destroy their reputation. And so, she will become a gossip and in the future she will be a master of gossip.