It sucks that the system penalizes you for trying to be a nice, honest person. You didn't think you were injured, and you knew that calling police / insurance would **** up the ladies life by a non-negligible amount.
But now she's reneging on her promise to help you, and promises don't count for **** in court.
I hope you at least have a couple witnesses backing your side of the story, so she doesn't try to claim you ran a red light and make you pay for her car.