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
I have once heard, that when kids are born and they are so wrinkled, that is because they are little old sages that are reborn in new body. Notice how they already know some things (like swimming) even though they arent taught about it, and devour information like sponged. So my motto is, while they and I can, I would try to give them as much experience as possible. And it will be their choice (when they are 18) what to do with that knowledge.
When my friends had a child, I often began to think - were our parents always reserved in front of us. Were they always calm and reasonable. And I understand that YES. And when we were children, we did not understand how difficult it was for them to keep themselves calm. And I understand that this means that it will be almost impossible for a gambler to pretend to be calm. Therefore, I am critically against gambling in front of children. Because children can be emotionally traumatized.
You know what can also traumatize a kid? If you cut of chickens head in front of them, or cut the throat of a ram in front of them. A lot of kids observe that, but that does not make them vegetarians, nor they did not grow up as a maniacs. Commenting on your post, it is a duty to keep on eye on emotions we show in front of them. That does not necessary has to be gambling related. Gamblers can show two main emotions, happiness or rage. Should we also not gamble in front of them to hide positive emotions? Or should we better teach them about emotions and behaviour?