mate of mine did the same thing, he barely rolled into the back of another car in a traffic que. There was no damage at all to either car - not even a scratch, but they swapped details 'just in case'. It was an old couple he ran into and they have tried to claim for whiplash, loss of earnings, etc etc etc.
It's an utter joke that anyone can take a claim like that seriously when there wasnt even a mark on the car!!!
You should say she reversed into you and claim for whiplash yourself!