I'm tempted to ask what our response will be when we are gambling and our kinds come to ask what we are doing. Do we lie to them or tell them the truth. At a certain age children become so inquisitive that they ask questions virtually in everything they see us do.
If the child is not of legal age to engage in gambling, provide a responsible response. Never offer answers that may have detrimental effects on them, as they represent the potential future generation. If necessary, you can steer the conversation towards safer topics for them.
Even though a child can search for answers online, our ethics as gamblers should underline that participation should be by one's own volition, not through invitations. The purpose of gambling is not to seek income as a side job, but to alleviate stress and provide entertainment. While gambling may carry its own moral implications, at the very least, refrain from introducing children to the world of gambling when they are not yet of legal age.