This post originally appeared on my LiveJournal in this entry, which may include a lively discussion in the comments.
I suspect that the structure of Chapter 8 (In the Attic) is affected by the expansion of the original story. (This is one of those places where I'm curious to look at the original shorter version.) The first half is something of a brisk summary of at least the first several months (maybe longer) of Sara's new life. But then the chapter returns to the morning after Sara first moves to the attic and begins a more detailed look at her new relationships. I'll cover the first part in this blog.
I feel that the first several paragraphs capture the trauma of Sara's sudden transition vividly: the physical discomfort, the emotional distress, the sense of being removed from herself and looking for something to hang on to, even if only the painful truth, "My papa is dead!" We get some foreshadowing of Melchizidec in the scampering noises she hears in the night. And then, the next day, it's as if her life as a student has been erased. Her belongings have disappeared from her old suite of rooms. Lavinia has reclaimed the position of honor closest to Miss Minchin. And Sara is assigned a task that actually suits her abilities perfectly: a sort of teaching assistant to watch over and coach the youngest students.
But beyond that, she is turned into something of a maid-of-all-work: cleaning, and shopping, and running errands, and anything else that the rest of the staff can dump on her. Anyone who has experienced a sudden change of occupation, and especially when the new one involves physical labor, can easily imagine how time would blur together as Sara simply tried to make it through each day. And yet she made time to continue studying on her own and she connects education with class very directly. If she doesn't hold on to the things she has learned, she fears that she will "be like poor Becky" and lose her upper class speech mannerisms.
Behavior is one of the few things Sara has control over. She now wears plain, shabby clothing that she is always outgrowing and that becomes an object of ridicule. And there is now an enormous social distance between her and the other students, even when she is interacting with them. Those interactions become more constrained when Sara is told to take her meals with the other servants. (For all of Miss Minchin's instruction that Sara's transition is to be immediate and complete, there does seem to be a more gradual withdrawal in some areas.)
In combination with Sara's decision to set the best, most hardworking example that she can, she survives emotionally through her role-playing. At first, she sees herself as a soldier like her papa. "Soldiers don't complain. I will pretend this is part of a war." It will be some time before she returns to the role of princess.