Bitcoin is helping all of us to earn extra money and if teenager wants to start earning then there is nothing wrong in it as it will make them more responsible and start valuing money from very early age so I think we should show them the simple ways of earning bitcoins instead of introducing them to trading and gambling.
I agree, bitcoin is the best way to make young people learn about responsibilities and how to earn their own money, doing things they already do every day, but also we need to supervise them and guide them because as we know bitcoin is used in gambling sites, and unless we dont want them to become gamblers we need to keep an eye on them and what do they actually do with the bitcoin they earn.