In that situation, take a photo of the spot she hit, then get another photo of the back of both your cars with the license plates visible. You can report their license plate number to your insurance company if she did any damage, and they will handle it.  A video that starts at the dent/scratch then moves to the back of the cars showing the license plates would be good too.  Cars don't get damaged as easily as they used to, but they are still status symbols and expensive to repair.