I usually fill a green dot card only for the temporary purchases in need within that month. After the first billing cycle IF YOU HAVENT USED THE FULL PORTION OF YOUR CARD THEY WILL DEDUCT 5.99 to 11.99 monthly. If you make online purchases frequently its ideal.
So I usually use the paper one to buy what i want and cancel the card and tell them Im not interested in the hard and real one. Its worthless to me then since I dont make other "discreet" purchases.
I think for ladies who require prepay options the refill card is the way to go since I dont have to call a 1800 number, register. or compromise a paper trail beside the cash I used to buy it.
There is a limit of 500 per card though, and some airline purchases wont be secured by its use. But she could always hit an atm and withdrawal it, redeposit in her account and work from there.