Thank you for your response, but the gift card has been redeemed already on my account. I am the family organizer with a gift card balance already.
and only YOU can use that gift card balance...
However, as the family organizer with a gift card balance, my daughter made a purchase and it was processed against my credit card, instead of my gift card balance. I think it's a glitch with family share. I see that I am not the only one with this problem.
This is how FamilySharing with Gift Cards is supposed to work.
Using gift cards in Family Sharing will charge against a gift card ONLY for purchases against that specific account.
You redeemed the gift card you you account so only purchases YOU make will go against that gift card.
If your daughter redeems a gift card, any purchases she makes will go against that gift card.
-> How iTunes Store purchases are billed - Apple Support
"How are Family Sharing purchases billed?
When you initiate a new purchase, it will be billed directly to the family organizer's account, unless you have gift or store credit. First, your store credit will be used to pay the partial or total bill. The remainder will bill to the family organizer. iTunes Store credit on your account isn't shared with other family members. So if the family organizer has a $50 credit on their account and another family member initiates a purchase, it won't deduct from the organizer's iTunes Store credit, but will bill the organizer's credit or debit card."