How do I use my store credit/vouchers as a purchasing point for my Children(family members) as opposed to my Credit Card in a family sharing setup?

Eel,

You have to redeem the gift cards to their account, not to yours. Here is how it works:

After you set up your family, any time a family member initiates a new purchase it will be billed directly to your account unless that family member has gift or store credit. First, their store credit will be used to pay the partial or total bill. The remainder will bill to the family organizer's card.

The store credit on your own account will only be used for purchases on your own account.

We had $28 in credit that we thought we could use for child purchases. We were disappointed to see the child's purchases go straight to credit card instead.

Our workaround is to have the child make a buy request but, the parent declines it and buys it on the organizer account instead. The child can then download the app or music from the organizer account.

After the $28 credit is used up then we'll put the store credit directly on the child's account.