I was in a similar situation about 18 months ago. Driving home from work, teenage kid runs into the road. He actually hit the front wing of my car and then goes into the windscreen. He fortunately got straight up although had a cut on his face. I helped him up and a crowd gathers, meanwhile I am feeling really shocked.
After 5 minutes or so his dad turns up, and starts throwing accusations and trying to get me to admit to driving too fast when I wasn't, and several witnesses were backing me up. I guess he was upset!
The police later tell me that he's going to make a claim and to get all my witness statements together, and about 3 months later, just when I'd stopped thinking about it non-stop, I received a letter from their claims company.
Thankfully my insurance company were very good and said they would fight my corner rather than just settle it out of court. The kid's claims company didn't take it any further, basically because they didn't do a very good job of making it look like my fault. So I was pretty lucky I think.
Get your witness statements in order now. If I hadn't done this right away, by the time I'd received the letter my evidence would have been far from water tight.
As for the damage to my car, I only needed a new windscreen which was about £150. The wing was also dented which I didn't bother fixing.
Frankly I was so shaken, and thankful not to have killed the guy despite the fact he was trying to sue me, I didn't even consider claiming off them. I guess if the damage was worse I might feel differently. I think in your case the parents ought to contribute something to your costs.
It has definitely made me look at how I drive, not that I was at fault in this case or reckless any other time, but who can honestly say they don't sometimes take risks?