Most parents don't even know if their kids have started gambling. The beginning of gambling lifestyle they tend to hide it more especially from their parents. I don't think parents have any power to decide when their kids should start gambling because most of them  don't even play gambling from the house.

It is better for a child to start playing gambling at the age that he can afford money for himself. When children starts paying gambling at a very tender age it usually make them to do dangerous things that can affect them.

I don't even think any parents will advice his/her child to start playing gambling because parents know the side effects of gambling which they would want to protect their kids from it.