How can my wife log out of her Family Sharing and join mine on iPhone?

Hi Ingo, thanks for your reply.

There is no fa il,y sharing active, as she's the only one left in that family group (that she created so still owner). When clicking the button, nothing happens. No errors, nothing.

When she tries to join "my" family, the error is related to her being already part of another family.

I don't know how to force the disband of the old family (1 member only), as when I click nothing happens.

Hi Ingo, yes. The issue is exactly that: when she taps "leave family", it does not work. And she's the only family member of that family... so I don't know what could be preventing that action.

Yep she's the Organizer (there were other members in this family, who have been successfully moved out). I'll contact the Apple Support to look into details, thank you!