Angry Tethering/Hotspot control

I have what probably is a strange request, but here goes:

I'm getting the kid a Galaxy S2 for Christmas - it costs just as much to add her to my plan as it does to buy the prepaid minutes for her

I need to know if there's an app out there that can "lock" the ability to use tethering and mobile hotspot. Yeah, I know she can just download a different tethering app from Google Play and use that, but I want to make it a little more difficult for her Ideally it would have a "schedule" where it can be locked out during certain times, or at the very least a "passcode" that can be entered to allow the access.

I'm not concerned with data usage, but at home I have the Wifi turn off at midnight so she'll actually go to bed, and I know if she can tether or use the hotspot she'll just do that and stay up and watch anime all night

So, is there something out there that can do this? My searches have been rather fruitless so far.