They’ve already tried that - they bought one, pulled it apart to see how it worked and couldn’t put it together again. There’s a Veritasium video about it.

EDIT: One other thought. If you and your wife have different phone hardware and especially if your hardware is very old, I believe that there’s hardware support required for WiFi calling support.

My phone is actually newer. I know wifi calling works on my phone because I had it enabled with our previous carrier.

I thought I’d try 1001 Albums You Must Hear Before You Die (I’m using https://1001albumsgenerator.com/ ), but it’s been a bit disappointing really - I’m nearly 800 in and only found 1 new artist to add to my collection. I guess I’m just old and set in my ways.