D.T.
Choices and rewards. She can choose to go to bed and still have all of her priviledges (like tv, radio, phone, activities, and toys--you only take one at a time for a bad choice) or she can choose to fight you about it and lose something. Then once you've seen her make 7 good choices in a row you can reward her by giving her something back or something new.
here's a website that helps understand what is going on.