I'd be hesiant to go this route, as once the money is on there you usually have a fee to get cash back. Plus, will she really want to use the card to buy a soda or treat for herself? That might be encouraging a bad habit to use plastic for everything.
I opened up a teen checking account at Wells Fargo for my teen daughter. I'm already an account holder there so there is no fee for her account. With the account, we get a debit card, a check book, and both a checking and savings account for her. It's linked to my account, and I have a duplicate debit card. I can go online, look at activity, transfer money right to her account, etc. It's great. Oh, and we were able to set limits as to how much she can withdraw and spend POS each day. This is a perfect setup for us. Last year when she traveled to DC I dreaded sending enough cash with her to get through the week. Not an issue anymore. I can change the limits at any time. And if she were stuck somewhere without enough money I can transfer right to her account instantly. I foresee her using this account all the way through college.
She has a small PT job and we have decided that 1/3 her check goes to savings, 1/3 to checking (for use with the card) and 1/3 cash for 'walking around' money. The bank can do all that for us when she makes a deposit.
It's the best of both worlds, I think. She has a small amount of cash that she learn how to be responsible with. She can learn how spending with plastic affects her net worth, and she's saving some too. (The savings also acts as overdraft protection.)