HELPHELPHELP, PLEEEASE. MY FRIEND MIGHT GO TO JAIL!?

So she threw a (soft squishy) ball at this other chick in gym. Hit her in the face. And that other girl cried and what not. So now shes trying to press charges. And im wondering if you can even go to jail or rehab/ A school for throwing a ball and hitting a girl in the face [it his her forehead]