When do I call my insurance company in a fender bender?

Yesterday, a girl who was looking at her cell phone bashed into the back of my car while I was waiting at a light. She immediately popped out of her car, gave me her insurance information, and apologized. I got the feeling this was not her first experience with this kind of accident.
I called her insurance, and was assured they would get back to me. They have, but not when I was available, and now are not getting back to me at all.
Should I call my own insurance company and report it, even though it is completely the other person’s fault? Or should I just wait a couple more days and see if they follow through?