Some people literally underestimate a kid's capability to learn something by just observing or watching, just remember that some of the children follow or imitate their parents as they see them as the one that guides them in life. Just for example, you are a good chef, if they know that you are a good cook, most probably they would like to be a chef as well when they grow up things like that. Even if you told them that gambling shouldn't be done by kids, they could still do it secretly so once they find it entertaining as you also do it as well, then for sure they would do gambling without hesitation. If you can't handle your gambling habits as you know to yourself that gambling is not good if handled poorly, then as a responsible parent you wouldn't even teach them in the first place.
The development of the times is very fast and now it is very modern in any case including technology, I more often see children today busy with their gadgets than reading books and if only initially they have seen gambling activities that you do then don't be surprised if suddenly you find them busy playing gadgets that turn out they have been involved in one of the online gambling situations, in addition to every casino lately always appears on some social media with a really big promotion, and that is a significant possibility.