This article covers the most popular options:

https://www.universalremotereviews.com/best-remotes-for-sonos/

But no physical remote will give you the amount of control the Sonos app gives you.

And when they do, they look very much like the app (like this one: SmartSwitch Lite (UK/EU) | VIOLET (violet-ultra.co.uk)), which makes your wife not want to use it.

I miss the Ikea remote (Ikea’s inexpensive Sonos remote control is worth every penny - The Verge) in the link provided by @GuitarSuperstar. Would your wife not like to use voice commands for Sonos (either via Google Assistant of through Alexa)?

The other Option is to hook up Alexa or Google Home, but you’d need to have a streaming service (you can use Free Spotify).  Then she can select music, radio, and adjust volume by room by voice.  That could make her appy!

Iets kleiner: https://violet-ultra.co.uk/product/smartswitch-lite-uk-eu/ Ik las er goede dingen over. Een iPad aan de wand monteren kan natuurlijk ook.