The kids have their x-mas money in on-chain wallets in cold storage. I have a link on their browser bookmark bar to view the status of their on-chain wallets with a blockchain explorer.

They have chore and spending money in lightning bluewallet lndhub. Since they're too young for their own phone, they are set up on their browser with Alby connected to bluewallet's lndhub (self hosted). Their wallet is also on my phone with bluewallet so I can create an invoice for them and pay it when they do chores, or when they want to spend it at the store.