I think it would be better if we just let children enjoy their lives. Since they are still dependent on their parents, they don't need to learn bitcoin ASAP and as technology advances and bitcoin grows, I think they'll know about it at the right time. In regards with teenagers, mostly they are into web browsing, side job hunting and tech exploring that's why it might be easier for them to learn about bitcoin with just little supervision. Just teach them the basics, how bitcoin works and what can we do with it, as long as they get interested into it, they will make a way to learn more about it.