Well, they weren't wearing helmets... why is that such a critical piece of information. If you're hit by a 4,000 lb car, that 200g helmet isn't going to do much for you.
Where was she riding? I ride through there pretty often and I'm a bit fatalistic about road riding - if you put in enough miles on a bike you are going to have an unpleasant (or worse) interaction with a car.
God bless her dad, he was a lot less bitter and angry than I would be if my daughter were killed.