You can put a time limit on the router, but with a little tech know-how from her friends, she could probably learn to by-pass it.
The best bet is to have physical possession of the router in your bedroom during the hours you don’t want her to have it. If her ability to practice self-control is low enough that you need to physically possess the router, I’d suggest getting a hand on her cell phone as well, lest she figures out that she can tether her phone to her computer and you end up with a horrid cell phone bill.
and you end up with a horrid cell phone bill.
I can tell you who should end up with that bill, and if it takes 5 years without a cell phone to pay it, so be it.
Personal accountability is a must or life becomes, let me see, Lindsey Lohan, just out of control.