I do not think any country should allow their gambling site (online) or offline to the children of their country. If they allow their child to gamble then the country is in the edge of losing the powerful asset for gambling. As they have not much knowledge and they can be affected more than an adult.
No problem with it since any good country will definitely protect the future of their potential leaders in the future. However, if the parents or guardians do not serve as role models but are showy to their kids that they are gambling,