How to disable OS update notifications in non admin accounts?

Hello.

I have noticed that in 10.8, the Notification Center will send an alert whenever a new OS update is available. Fine.

The problem is that if you have multiple users on one Mac, all of them get that annoying message, even my kids who have no idea why this is popping up in there account. Worse, if I then install the update as an admin, the notification disappears from my account but remains in all others! And when I click on the "Details" option in their account, I have to enter the admin pwd only to see the App Store app load up and tell me that there are no new updates available!

After searching on this board, I understand one can disable ALL notifications for individual account by using the following method:

Open Terminal and enter the following command:

launchctl unload -w /System/Library/LaunchAgents/com.apple.notificationcenterui.plist

Next type the following command to kill NotificationCenter:

killall NotificationCenter

Finally, quit out of Terminal and return to Finder

- See more at: http://osxdaily.com/2012/08/06/disable-notification-center-remove-menu-bar-icon- os-x/#sthash.WdKyAhfB.dpuf

But how can I simply tell the Notifications center to realize that if I install the OS update in the admin account, I shouldn't need to go into each user account and turn off that **** alert message without turning off the useful notificatiosn like new mail etc...

Thanks a lot for any help.

Bo