Well, this one has me stumped. Family Sharing is indeed appearing as an option, but as a developer it is not something that I have explicitly activated or de-activated apart from agreeing to it in the developer agreement; which is to say I don't know why it is shown as sharable unless it is a default option set by Apple. I agree it should be sharable.
But I have never used the Family Sharing feature myself, so this is new territory. A search turned up this
link with good instructions:
Use your iPhone or iPad to download content that family members purchased
- Open the App Store, Apple TV app, or Apple Books.
- Find your family member's purchases.
- App Store: Tap your profile picture at the top of the screen, then tap Purchased.
- Apple TV app: Tap the Library tab, then tap Family Sharing.
- Apple Books: Tap your profile picture at the top of the screen.
- Tap your family member's name to see their content. Learn what to do if you don’t see any content or can't tap your family member.
- To download an item, tap the Download button next to it.
I should add that the sharing qr/link in the app menu exists in a world apart from Family Sharing. I put it there to help you help me help other pilgrims find the app.
Do let me know if the instructions above work, and thanks for the support!