Better teach kids that gambling is for fun, not for money making, and show examples how they really can earn, and there will be much fewer problems.
In that case a kid could have a question,
why someone has to play with real money just to have fun. This question sound very reasonable to me. After all, there are lots of other ways to have fun, without risking your money and possibility to end up in debts and with an addiction. What a parent should tell his child about that? I get your point about the necessity of drawing a line between gambling and earning. But my point is what is the argument to support precisely gambling as a way of having fun?
I have a pretty simple explanation for a kid in this case: "adults can use real money to gamble to have fun, when you grow up and have your own money, you can do with them whatever you want." And additional argument "adults can ride real cars, but because you are still young, you can ride only bicycle or car with pedals". But like you have said, there is plenty of ways to have fun, that is why kids wont pay much attention to gambling, as he will get fun from more simple things, the things that he understands.
My idea from the beginning was not to teach gambling as this is a way to have fun, but not to hide it on purpose, and if a kid ask, give explanation, give examples. I dont support teaching on purpose, but if kid noticed you gamble, just give an explanation of what you are doing. Instead of quickly closing browser or cleaning table from chips, cards or whatever is used to gamble.
Honesty is my motto. Kid are smarter than we think, and they deserve the truth, even about grown-up problems. Teaching is more than telling
Begin by calling gambling an adult activity. Driving and biking get you someplace, but one requires more responsibility. We must go deeper. Children observe and copy us. Show children that gambling, like any adult choice, has repercussions
Not to scare kids, but to educate critical thinking. Talk about risks, benefits, and self-control. Teach kids that even adults can make wrong choices, so we must be vigilant
Children are sponges. They embrace everything. We should teach them to ask the correct questions about gambling and life. We raise knowledgeable, responsible adults who make informed, not impulsive, decisions that way