If you're not getting push notifications, check these four things first — this covers the vast majority of cases:
Push notifications must be enabled in your financial institution's online banking settings.
Both the parent and the child must have logged into the app at least once.
The child must log in on a mobile device (not a browser) for push notifications to register on that device.
The action has to involve a different account than the one it's tied to — a parent won't get a push notification for an action on their own account triggering itself.
If all four are confirmed and you're still not receiving notifications, contact support with the specific date/time and action that should have triggered the alert so it can be investigated further.