I'd like to know why she didn't get a ticket... To me it sounds like the officer thinks you both were responsiable for the accident. I would have insisted she get a ticket!

Be prepared, they (insurance companies) are going to want to know what YOU did to prevent the accident... They always have to ask that, even if you were at a dead stop, waiting for a light and someone rear ends YOU!...
and yup, wait until in the morning to see how you feel. I would take something tonight at bedtime to try to ward off any stiffness/soreness in the morning.

I had a friend that was rear ended on her way to work one day. She was fine and went on to work. She worked for 2 1/2 days... on that 3rd day, she sat down and her legs went out on her completely, couldn't feel them or use them and she was rushed to the hospital where she ended up in traction from that wreck.