I need a name for a character in my story Help!?

I am writing a story about a girl named Kaia who goes to a brand new school and meets this group of girls who are really nice to her. one of the girls named Lexi warns her about the leader of the group saying she is dangerous and that Kaia should stay away from her. A couple days l8r Lexi is found dead. I was wondering wat the leader's name should be. She is tall, blonde, has blue eyes, and she is very nice at first then very manipulative. I really want her name to be girly but kinda menacing in a way. Thanks :)