Finding someone else’s phone
My wife and I both have iPhone 13’s. Is there a way I can add her phone to my devices so in the event that her phone is lost I can find it from my phone and vice versa.
One option: Share your location with your family - Apple Support
Also note that even without that option on, either of you can use any Internet browser on any device and log into www.icloud.com/find using the other person's Apple ID and password.