I'm guessing the kids want the notifications and the mom doesn't want to go in and modify the setting in all the apps across all the phones (I sure wouldn't). I think an easier approach would be to simply put them into do not disturb mode.

Correct. She’s not into micromanagement and it’s not only about the notifications.

I don’t think she wants to log into the phones. She just puts them on vibrate and into her bag ;)