When I was in high school (many moons ago), we had lots of homework… which I disagreed with. School time should be for learning, and home time should be leisure time or doing a few chores.
We had lots of homework but not 24/7. As Amanda has suggested, check with the school Principal or Teachers to find out if your daughter being computer bound with homework 24/7 is warranted. Maybe she is pulling the wool over your eyes and is on Farcebook and in chat rooms.
Teachers nowadays are glorified child sitters. Kids are self taught… especially with having the Internet. Limitless information at your fingertips…