Hi Don,
If your wife is using Outlook Desktop app, chances are the Microsoft 365 account for work has been removed from the current Outlook profile. Please kindly try adding email accounts into Outlook for Mac to see if she is able to add the work account back in the current profile.
If the account is already in this Outlook profile, to further check if it is related to this profile, please kindly switch to a new Outlook profile to see if you are able to add the accounts there. For more information, please refer to Manage profiles or identities in Outlook for Mac.
If you are using Outlook on the web, to see if it is related to the current Chrome Browser, please kindly sign into the work account using a different browser to see if it helps. If not, please kindly try signing in in a InPrivate/Incognito window to see if you are able to sign in there.
Hope this helps. Please feel free to let us know if there are any updates from you. If none of the above works, to better help you with your question, please kindly provide us the above test results and some screenshot of the login page, profile account page and any error messages for further analysis. Thank you for your patience and cooperation:)
Best regards,
Jasmine