Ok, logon to your user account. Start OE6 and select Tools from the menu bar and then select Accounts. There should only be your email account listed. If your wifes is also there, you should delete/de-select it.
Login to the other user account and repeat, but removing your email account.
If you can provide details of what email accounts have been setup in each user account, we can help. Provide as much detail as you can in your post as it saves us having to come back and ask.