Family sharing but allow other adults also to make their own purchases
I purchased a family subscription to Apple Music and want to set up a "family" that includes my partner and 18+ son. My partner wants to be able to make her own purchases in the App store, but the minute she joins the "family," her Apple id becomes nonfunctional and she appears only to be able to make purchases by using my credit card. (That of course involves constraints about permission or passwords or whatever.)
Is there any way to allow her to share the music plan but remain her own person for other aspects of the Apple/iCloud ecology?
iMac 27", macOS 10.15