[dealingwithit] do what you think is right... get her to pay for re-habillitation / physio if you need it, medical bills, a helmet, maybe even a new bike, all dependant on what was damaged/lost
and for the record I had a similar story which convinced me to buy my helmet last year (i got real lucky and only ended up with a really messed up wrist for 3 months and about 6 months of recovery.)
I was going not even 5mph turning the corner and there comes a car not looking (don't ask how) facing right at me for a head on collision. I messed up my wrist and almost landed on my head. From that day until 1 season later I put my bike away until I went out and bought my bike helmet. I originally bought a Catlike Kompact and a GIRO transfer, but before even opening the CATLIKE box I returned it, got a pair of shoes and some money back. The GIRO transfer cost me about 45$ after tax and is a very decent helmet.
Since then, even with my helmet I have been in 2 accidents... same story every single time, driver in a rush, turns the corner without looking and i get the blunt end of it. Needless to say the other 2 times I didnt land on my head either but am i ever glad I have that helmet with me.