No surprise. It's likely the other party didn't want to cooperate, and Watkins is a college student, the solicitor was unlikely to push for anything.
Charges being dismissed for college arguments, threats, even fights is common. Barely a week goes by that some student isn't involved in a fight in a dorm or something. Typically, some internal discipline is handed out, maybe probation of some type, and that's it.
Good for Watkins. Now, hopefully she can earn her way back into Staley's good graces very quickly. I expect that's been the toughest part given Staley has been known to kick good players off the team when they weren't doing what she expected.