Your post isn't really clear.
What do you mean by "top up ... with credit"?
What exactly are you trying to purchase?
Membership plan, add-ons, cash credit?
What do you mean by "no option to pay from credit"?
Do you mean no option to pay for membership or add-ons using cash credit already on the account?
If you're using the Gift Shop then you can't pay for stuff using cash credit on your own account.
The only payment option on the Gift Shop is card.
If you're using her account then once the price of whatever you're buying is less than the cash credit balance on her account then you should get the option to pay using cash credit.
Please clarify exactly what you're trying to do, what steps you're taking to do it, what happens, if you're using your own account and the Gift Shop or using your daughter's account when trying to buy stuff.
If you have cash credit on your own account but want to use that to buy stuff on your daughter's account then you'll have to contact 48 support to ask them if they might be able to transfer the cash credit from your account to your daughter's.
If you need to contact 48 support about this then see the links in my signature below.
