Did she get burned, or did they find out she’s a shallow bitch?
What difference does it make? For one thing, all teenaged girls are “shallow,” at least compared to most adults. And there’s nothing wrong with a dating couple’s ceasing to date one another, or one party’s deciding no longer to date.
My point is that she was hurt, which is entirely predictable, and she has apparently responded with entirely predictable, but sad, cynicism and aggressiveness.