I just found out that a girl who has been there only two more weeks than I is making $0.25 more an hour than I, and only because she is friends with the manager.

But this is a MAJOR reason why we are not allowed to discuss pay with other employees, for that exact reason. BUT if you feel that you deserve a raise, then by all means, fight it. Sometimes employers LIKE seeing employees be up front with them and standing up for themselves, not a push over, you know?