Suing would be a great idea but you're ignoring the downsides of a lawsuit. Uber has a lot of money, they could effectively drag it out for a very long time. Even worse, most of her proof is likely on some Uber computers / servers which could go "mysteriously" missing in which case she could be made out to be a liar through a court loss thus possibly making it harder to join another company because she's "that girl".

Even if they can get it rushed through the count payment takes forever by which time she would likely owe a lot of money to a lawyer.

Ideally she would sue, win quickly if the allegations are true, and move on. But when does that ever happen?