Well, that's just for one day. Is it possible that she needs the extra time to learn the songs and choreography? There's a good chance that she'll learn the modified version of the choreography that is usually utilized for non-professional theatre Roxies. (or as some would call it....Roxie lite).
"Noel [Coward] and I were in Paris once. Adjoining rooms, of course. One night, I felt mischievous, so I knocked on Noel's door, and he asked, 'Who is it?' I lowered my voice and said 'Hotel detective. Have you got a gentleman in your room?' He answered, 'Just a minute, I'll ask him.'" (Beatrice Lillie)