~OP~
I would definitely provide my documents for my child to receive the winnings if I were in a similar situation, but after that I would have a constructive conversation with him about the dangers of gambling addiction and the importance of self-control. I am not opposed to minors gambling, as I have been gambling since I was 12 and do not see anything wrong with it. I am opposed to the abuse of gambling, regardless of the age of the gambler.
This has been the opinion of most members here; at least nobody will want to leave that money with the casino without trying to get it out for their side. What's more important is the step to take afterward since it's hard to let go of that winning.
In the aspect of a minor being allowed to gamble, some will say as long as the child is making money of their own, they are allowed to decide whatever they want to do with it, but in my own opinion, I still think it's right the child should wait till they are of age before they start, as they could havestronger emotional control compared to when they are tender.