Q: how to delete family share

With family sharing the organiser will be charged for a member's purchases unless that family member has a balance on their account : Family purchases and payments - Apple Support

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. As the family organizer, any receipts generated by the transaction will be sent to you.

There are instructions on this page for managing and stopping auto-renewing subscriptions : Manage your auto-renewing subscriptions.

If you want to disband a family group : Leave Family Sharing - Apple Support