Baruch Hashem everyone is okay!
If someone suggested she leave, the probability is she didn’t sustain damage. Otherwise it would be easily provable she engaged in a hit and run. Either way, if she left she may deny involvement, and it will be a he-said she-said situation. Do you think even if you find her anything constructive will be accomplished?
Do you have any witnesses who can identify her? Who advised her to leave? Is it possible she told that person she doesn’t think she was involved, so he told her to leave? (Although that is doubtful if she stopped in the first place, unless she only stopped because she thought maybe someone was hurt and left when told everyone was okay.)