A real concern here to keep in mind: while most of us (and I'll bet the OP, too) enjoy the friendliness that seems to go with camping, having an apparently unsupervised youngster wanting so badly to help could lead to one of those unintended consequences: someone, even the child...remember Murphy's laws...getting hurt. Yes, we have a pretty litigious society now and you never know who will take it in stride (we're thinking a cut or scrape or pinch...please nothing serious!) or who will make trouble. Sad, but something we all have to think about these days:(
That's the main reason I am a little nervous about being "volunteered" to watch a stranger's child just because we're nice "grandparents" and the "parents" want a break. Now if it's a friend's child and they're even along...Grandma and her little charge are gonna have some fun:)
FWIW, the OP did post quite a lengthy post (and I'm rambling I think...sorry)...I'd have not bothered with that...I've been known to forget such incidences. But then if the child had bothered us that much, you can bet we'd have made a point to meet his parents if only to ensure the child's safety and hopefully make some new friends...like I said, DH is great at taking that lead and I have objections to following:)