The Gmail Browser Add-on will show the tasks for the currently logged-in Remember The Milk account regardless of which Gmail account is logged in. For this reason, it may be best to log out of your account in environments where there are multiple Gmail users on a machine.
Alternatively, you can hide the add-on for one account only. While logged in to your wife's account, click on the small arrow to the left of the add-on's task pane. This will minimize the add-on and the setting will be remembered for her account.
Hope this helps!
Posted 2 years ago