On her phone, within Sonos app, go to Account > App Preferences > Reset App

Then re-open app and select Join Existing System when prompted.

Hi.  Your wife needs to uninstall the Sonos app on her phone.  Then install it again, choosing to connect to an existing system.  To be able to access settings, your wife will need to enter the email address and password for the system (same as yours).

It sounds like you might be trying that anyway, but it really should work.

Edit: you must make sure that everything is on the same network, indeed subnet.

Thank you for your quick answer. It was perfect.

I would like to follow up on the issue above. I have the same setup as Sndd. I used the instructions above and generaly is working but I have to connect to Sonos from my phone first and than my wife`s phone. If she is connecting first then can't see any services. So the problem is when I am out of home.

Is there some solution of this behaviour? Thanks a lot for any suggestion.