Children aged -15 years are never suitable for gambling because it can damage their behavior later in life.
It depends on their mindset. At the age of 15, I doubt they will have an interest on doing gambling.
But if they really did, more on it was because of their curiosity. I'm sure at that age they already know the difference between what's the good thing to do and not. If we try to force and convince them to ignore gambling the more they want to know about it.
Today's 15-year-olds are very smart, they know that in a casino the chances of winning are very low, they seek more fun than the same money, because most of them have no obligations, I know a neighbor who is 14 years old. And what he did was play warm and then from there he went to Axie Infinity, all the time every day I think he gets the 150SLP, every day, he also plays others like cryptoblade, plants, something like that and from all those games he always accumulates a lot of money And the most important thing is that he says that he does it because he likes it, that he knows he has money but he does it for fun, it should be noted that this child spends all day on a PC playing.
Environment influences kids so if they see grown up doing it, they will also be doing it. I for example grew up where my parents are not around but with my brothers inviting a crowd under our basement and play cards and billiards. Its not surprising that even my sister knows how to deal cards like a pro.
So if gambling is exposed to children, its got an effect on them but the good part is that they learn and may not be addicted to it when they grew old. Because the interest of the kids changes over time.