If my wife inadvertently changed her password she doesn't know what the new one might be. Can you send a temp password to her alt contact?

You can only regain use of your account if there is a current recovery email or phone even if a hacker changed it. You must have a recovery email or phone. If you only have one and can't use it there is no other method other than what the next paragraph indicates.

There is a new paid service called Yahoo Account Pro. Details at this link. https://productcentral.yahoo.com/products/yahoo-ac...

It is possible that they can be of help but there is no guarantee that paying for the service will solve your problem. There is no other paid service. This is only available in the US.

Security questions were eliminated many years ago and are only used for old accounts where there is no recovery email or phone. You can remove them now under account security. They may have already been removed. For details go here. https://help.yahoo.com/kb/account/delete-havent-re...

If the account was closed for non use for a year or for TOS violations such as being underage in your country it can't be recovered. You will see a message that the account is not there.

To recover an account or to get a list of accounts associated with a recovery phone number or email address go here. https://login.yahoo.com/forgot

Do not use this method to just change your password if you know the old one. Just go to Account Security under Account Info or go here. https://edit.yahoo.com/config/change_pw

For more details go here. https://help.yahoo.com/kb/mail/SLN2035.html

What's wrong with the good old fashioned 'send me an email password unlock'?