It is normal, many times many parents don't want their children to gamble and many parents don't like gambling so children don't sit without gambling. Now if I understand gambling well and if I am an adult and if my family and my parents don't like my gambling then I can play this game without telling them. As we get the benefit of online casino, we can easily gamble with our smart phone or any other device and no one will know about it unless I tell about it. I gamble but I don't like to tell anyone about this because here I am risking my money so why should I tell others about this and why will everyone discuss or criticize me. So if there is such pressure from one's family, I think one should gamble secretly without arguing with his family.
The kind of experience some parents have makes them lose interest and disallowed their children to have fun about some things and I think gambling is one of the few things parents doesn't joke about. Some of them during their kids era, gambling was such a top that can makes a child mislead into something they shouldn't have done in the first place, it's that phobia that hunt then and by the time they see anything concerning gambling, they frown at it.
Though, some parents naturally don't want gambling and not on the perspective of addiction but on the religious aspect. Muslim Ummah dislike gambling because it's a sin before their creation and bad for gambling, seeing kids can make them be so mad at them and eve deny them some things, this is not limited to Muslims only, there are other religions that doesn't like gambling, and any parent found between those religions hate gambling anything related to gambling.