How can I find my wife's iphone on my MacBook when we don't have the same family ID using the Find My app?
She can sign in to sign in to iCloud.com/find with her apple ID and password
From:
If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support
Additionally:
There’s really no such thing as a “FamilyID.”
ALL AppleIDs are intended to be for individuals.
So, the individual AppleIDs are “logically joined” together into Family Sharing.
Family Sharing has additional FindMy features built-in. (very helpful when trying to find your partner’s device - w/o any additional sign-in being required.
See:
Set up Family Sharing - Apple Support
Then:
Share your location with your family - Apple Support
Find My
