Two years ago my daughter wanted some money for Christmas so I put it on a pre paid debit card called Osper. She's had it for years and it's really a neat solution for dealing with teenagers and money.
I've got a standing orders that transfers her allowance every week automatically. If she needs some more money, I use the app to transfer it instantly with a few clicks. She uses it to buy her own stuff on eBay so she's not messing with my account, although you can turn off internet if needed. I can see everything she's spent. If she needs cash, she can take it out of the ATM. She can use it in any store but her money can't be lost or stolen.
It's free for the first year, 10 quid a year after that.
