Sounds like it was an accident and that you didn't do anything wrong, like speeding or drinking or driving. I say this because my son was hit while riding his bike. Here's our thoughts as the family from the other end of the equation.
It was an accident, not brought on by negligent driving. My son will always bear the scares as a reminder to be more careful. The girl who hit him was in her late teens. She let my son use her cell phone to call home. My son wasn't wearing a helmet (he was repeatedly reminded of this - by the two cops, the firefighters, and myself).
The girl called the next day to pass on some her insurance had said and she asked how my son was doing. Her voice was quivering and it was obvious she was nervous. I let her know he would be fine and thanked her for calling. I was never angry at her. The only thing, I wish she hadn't told me, was about the accident. I knew she hit him (and I swear the only reason he didn't knock his head on the pavement was from all his judo lessons - they teach, read drill it into them, kids how to take a fall and slap their arm down keeping their head up. Guess what part of his body was shredded? His elbow) sorry, way off track. She hit him with the front of her car, but I didn't know she dragged him a bit. She shared that in her phone call and it was a visual I would have been happy not knowing.
We hold no anger to the girl. We had a long talk with our son about riding his bike safely (no one does anything without a helmet), we also told him she will bare the scars emotionally, hitting her brakes whenever anything catches her eye.
My son never rode another bike.
If the girl were to call us all these years later, I'd still be nice to her. She suffered just as much. We feel for the anguish she must have felt.
Do what you need to bring closure for yourself. Maybe talking to the family would be a good idea.