There's actually no camping at Fruit Bat Falls. The campsites are at Eliot Falls. You must have Cape York overload or had a few too many beers last night Mark
We had 4 nights there with our kids and they absolutely loved it. If you're there in the school holidays, the rangers also do free activities with the kids.
Within walking distance of the campsites are Twin Falls (great for younger kids as it's shallower and easier to access), Eliot(or Indian Head Falls (great for bigger kids who like jumping off heights), and the Saucepan(nice deep swimming hole with a beautiful little waterfall that our kids spent hours jumping into).
Fruit Bat Falls are beautiful too, but they are day use only, and a couple of kms back down the track past Scrubby Creek.
The kids of all ages loved the tour we did in Cooktown with Willie Gordon of Guurrbi Tours. Fantastic day.
http://www.guurrbitours.com/site/tours/At the Tip, we stayed at Punsand Bay because it had a pool so the kids could swim. The beach is great too but you are a little further away from the shops should you need them. You camp in amongst the trees right on the beach, so if you don't like trees like one couple we overheard up there, you might prefer Loyalty Beach or Alau Beach (at Umagico).
Another spot along the Old Telegraph Track that the kids loved was the Dulhunty River. Easy access to the water and they spent hours playing at the waterfall. You camp literally steps from the water.
My kids were 11 and 13, but we had 8 kids all together in our group ranging from 18 months through to 14 years.
I've started a trip report on here with loads of photos and hopefully some helpful info too, but it's a work in progress. Hopefully I'll be finished by the time you go
http://www.myswag.org/index.php?topic=25497.0Our kids found things to amuse themselves just about everywhere.
Have fun planning
Cheers
Karen