This is a known issue and Apple/Sonos are apparently working to get it fixed - there are other threads about it in the community here. The current (quick) workaround is to try another controller device for the setup, preferably one running iOS, that’s if you do have one to hand, or maybe wait for the fix.

Thank you for your prompt response.

I run my Apple Music through Sonos too (iOS and all working). If I go into manage services/add Apple/already a member etc will my wifes details appear or will I simply join twice! We have Apple family - but very different songs!

Do you imagine the fix is days or weeks or months...we’re patient people..

Apple Music (AM) is not something I use,  but I assume it’s best to do it with the Apple Music App on the mobile device logged-in first of all with your Wife’s credentials - but perhaps others here maybe able to guide you better than myself.

I assume the credentials are entered/stored through this icon-link in the AM App, but not really sure. (See screenshot attached).

Okay, thanks again