Does your mother also play Candy Crush – a lot? And needs help to enter the next level at 2am when you’re trying to sleep, making your phone alert when receiving the notification? You can mute notifications for all Facebook Applications individually.
Go to Settings -> Notifications, go down to App requests and activity and click on Edit. In the list that pulls up, click on the pull-down menu and change every app you want to Off. There is no “turn off all” option, these apps have to be selected individually.