put my wifes email addres on my macx

If you want to sign her into iCloud, iTunes, and other services that require an Apple ID, it would be better to create a separate user account for her using System Preferences/Users & Groups. She can sign into that account and stay signed in. It will also keep your data separate.

Open system preferences > iCloud in the window again click on iCloud , and fill up the iCloud mail address that your wife previously created .

See the article https://support.apple.com/en-hk/guide/mac-help/mh35565/mac

You have to fill up the Apple ID password of her , and click on next and follow the upcoming instructions if the Apple ID is created with secondary authentication or 2FA .