While sometimes I think people occasionally abuse the right of free speech, in this case, she was honest and said what she felt.
As far as the diploma, they have no right withholding it. She more than met the requirements to graduate and earned the diploma. She broke no laws, harmed noone, and owes them nothing.
I am sure a lawyer can get this cleared up soon enough.
While it's easy to applaud her honesty, the reality she will have to learn is that there is a time and place for everything, and brutal honesty at the wrong time will not further her career. She needs to learn timing and context.
dago