You know, that's was actually a very nice thing of that lady to do, the right thing to do!
I best at least 80% look around to see if anyone saw it and drive away.
Now, you could of course "soak" here for all it's worth, her premiums would go up.
If she left a number, you could also phone her first and see what shape she's in and cut her some slack and offer to come to some sort of agreement.
I know, I know ... screw her, her fault and a fat insurance cheque get's you an LSE bumper, possible two brand new "matching" HID's but ... she could have just as fast left you holding the bill.
Give it some thought, she could be a struggling single mom.
No one says you owe it to her to cut her some slack.
You know, you can find cheaper parts or even used parts that are as good as new
and you could even do all the work yourself and have her pay you cash for your time.
~ just thinking out loud !
but yeah, don't sacrifice on the outcome of the appearance of your LS of course.
It needs to be restored to condition prior to her little back up "oopsy!"
She may very well have plenty of money and she may very well, really appreciate going around the insurance company.
As long as your are compensated for the damaged where you are satisfied.
Good on her for leaving a note though! Not many people would!