Unless, it is not the kid that is gambling but someone at a right age that doesn't wanna get tracked down right? Well, the point is, the age restriction system will not really work here unless they implement KYC system with real time verification. Because merely, an ID's could still be used to steal identity to a person if they really want to gamble with a restricted age.

I probably say, there's nothing wrong with gambling, even a kid could play, but make sure he has a supervision with his parents and should know his limitation and responsibility.