Use a second iPhone with HomePod mini

See Use AirPlay to stream audio - Apple Support. It might pay to reboot your router and your wife's iPhone, then confirm it is connecting properly to your Wi-Fi network.

tt2

Hey there htanzman,

Thanks for reaching out to the Apple Support Communities. If having issues with sharing control of your accessories in your home, have you had a chance to work through the steps in the following resource: Share control of your home - Apple Support

If you can't share control of a home

- If you can no longer connect to a home, or receive or accept a home invitation, learn what to do.

- To invite people to control your home while you're away and edit permissions for them, you need to set up a home hub. If you don't have a home hub set up, you can only invite people when you're home and connected to your home Wi-Fi network. Matter-enabled accessories require a home hub, such as Apple TV 4K or HomePod mini.

- If Home has been upgraded to the new Home architecture, you must set up a home hub to share control of your home.

- You and the people you invite need the latest version of iOS, iPadOS, or macOS.

- Make sure that you and the people you invite are signed in to iCloud on iPhone, iPad, or Mac. In iCloud settings, turn on Home.

- Make sure that you and the people you invite haven't blocked each other's phone number or Apple ID. Learn how to manage blocked phone numbers, contacts, and emails on iPhone or iPad and how to manage blocked callers on Mac.

If still having issues after going through the steps above, we'd recommend reaching out to Apple Support directly from this next link here: Get Support - Apple

Take care!

Same problem. How did you resolve?