Right, now I understand. The dialog is there because the file password is *not* the same as your sign in password. The tooltip is there to help you realize that it does not make sense to enter the sign in password again, because the whole reason for the file password dialog is that the sign in password does not work.
I’d certainly ask if you wife has opened and modified the file recently, since that will re-encrypt the file with her password. To share a file like that, that’s what we have the key-sharing feature for. Setup up the file to be shared with both of you, and all should work without problems.