If my kid that's gambling secretly without my consent and he wins big, I will allow him to use my KYC since he has being gambling with my money and not his because he's not working. However, that will be the last day that I will allow him gamble until he reaches the right age. But if you look at it from this angle, any kid that wins such huge amount can take your document secretly and use it for KYC, only if he does not know any account he can use to withdraw the money.