That's good for you and your child, that means you have to teach and introduce bitcoin to your child. But kids usually just want to have fun and a pedestal to learn. So you should not force them to know and do what you do in bitcoin. Let them do what they want. If you want to keep bitcoin for your child but they do not want to know, you can entrust the bitcoin you keep to your relatives and give it to him to give it to your son someday.
I am actually amazed by this subject but who knows right? You will never know what tomorrow will be. If you do save Bitcoins for your child's future, then that is entirely up to you. We all never know what the future has in store for us anyway. Just my two cents, why not let us all save and invest to grow whatever we have for the future generation right? I think that is our idea: to give our successors a better life as compared to ours!
Kudos to you for saving Bitcoins for your child!