Ok so here is my stupid idea before I forget so let say I have 5 kids and I give them all access to a Bitcoin wallet on layer 3 most likely though a family run federation each kid has a hot wallet as well as a cold wallet. The hot wallet can do the normal send, receiving and storing of eCash both online and offline and the cold wallet will be a 3 of 5 dynamic multisig between the 5 children to be saved or spent at their own discretion. That's the basic idea 💡.