It is very risky, but for those who have one child they can share their private key with their child so security will be maintained if something happens to someone, whether death or illness, which makes them unable to access or work in the crypto world.
It is good to show your children your keys but it depends the character of your children, because you can give your child your key within some period of time your coins will be moved from your wallet, i consider only one reason why people are curious to always suggest of given out or showing a family members a private key, is because of death, what is important is to teach your child bitcoin and give them the guidelines of bitcoin because of death, save your private key and keep to a place that can be seen if you are no more than showing it to them when you are alive, why cryptocurrency private key is called private key is because it is personal