In reply to flopsicle:
The thing is it's a bit difficult to define supervision for bouldering. With roped walls, an easy way to do it is to say that the supervisor can't leave the ground unless a second supervisor is present, and a supervisor must tail the rope when the novice/kid is belaying. There isn't much running around on a roped wall other than that, and nobody is likely to fall on anybody's head.
With bouldering, it all feels like a soft-play centre until somebody lands on your head. (I've had kids run under me before as well, including once just as I fell off - I screamed for them to get out of the way and the parent grabbed them just in time - had all 18 stone of me landed on them I would expect I could have killed them, or at least caused very severe injuries).
I've seen "kids under a certain age must be within arms reach of an adult" - maybe that *isn't* too much? Perhaps add to that "any parent who is seen not to be in control of their children (e.g. they are running around) will be asked to leave without refund" - and enforce it at the first offence?
TBH, I think young kids are far better roped climbing. Might there actually be a case for no bouldering *at all* for under 10s, or maybe 12s, unless part of an instructed group? Then again that disadvantages kids like yours who sound like they know how to behave.
Neil
Post edited at 16:15