I will not pressurized my kids to learn about bitcoin at that early stage and I will ask them to have concentrate on studies and have fun in their childhood days instead of getting them into money matters.
I this era's kids are very mature in their very young age, they know the importance of money as they know the importance of education. teaching them about bitcoin in a fun way without pressurizing is not bad.
Kids are much active, but they need to be given the freedom to learn the one interests them rather than just pushing them to focus on a particular thing. This will explore them go out of it at some point. Better is to describe it and if they wish let them start to know more about it. Else let them enjoy the childhood days which would never come back again.