I'm sorry that this has happened. You are caught between a rock and a hard place, report to her insurance and you too will more than likely get clobbered at renewal.
Even if you report to police it could back fire on you.
Time for a dash cam?
Mind you, at 72 and driving an old banger you don't care about, you could be forgiven for colliding with her car some time in the future
"Accidents" happen
macafee2