Alisha Evans is character in The Worst Thing About My Sister.
She is known as Marty's classmate, and Marty dislikes her terribly. Alisha invites Marty to her birthday, but she laughs at her after that and calls her Bluebottle because of the horrible blue dress Marty's mother made for Marty for the party.
Alisha is spoiled, fat and usually wears her hair in a bun. Alisha sucks up to the two mean bullies in her class Katie and Ingrid, so that they will not pick on her. In the book, Alisha does not appear to have interacted with Melissa very much.