Bitcoin can be a way of saving but not intended for kids. Maybe if they already reach the right age it can be explained to them but not now, there have a right time. If they know the value of money and how hard to earn this money's that came from their parents. In my opinion it is right that we should teach our kids about bitcoins as early.
Bitcoin will be too much for kids to understand and beside shouldn't be the knowledge for saving start within the house and learned from the parents. Children should learn saving fiat money first because, growing up, this kind of money is what they will be used to. Bitcoin is not yet legalized and not all people are open-minded in understanding bitcoin, it might just confused the kids.