If they can control themselves from the effect of gambling, they can playing gambling to have fun. But many people doesn't realizes or not sure about themselves so that makes them gets deeper in gambling without have a chance to quit gambling easily. When someone tempts from gambling, they will not see that's a fast way for them to spends their money especially if they don't have a good control instead they will just thinks that's a way for them to wins much money.
As a matter of fact, when an adult can't control their emotions when they are gambling, so how can we expect children to be so responsible that they won't be influenced by the negative vibes of gambling whether it be the use of excessive funds or keep on gambling to chase loses etc. To be honest, children can get the negative effects of gambling much more quickly as compared to adults.
It's better adult people not playing gambling in front of their children if they don't wants their children curious about what they do. Adult people doesn't knows when their children will playing gambling with their friends because their children can do that secretly. Adult people must guided their children carefully and doesn't have to show their gambling activities to their children.
When you are living at home with kids living with you, there is no way you can hide your gambling activities and kids will usually follow you or at least be curious to know where you are spending your time. Unless kids are very small, then it is a separate thing but with the kids of age 5 and above, its very hard to gamble without them being aware of your activities.