I think it is enjambment.
Ms. Slade's manager in the minor character in this passage. This is the case being that they only had so much to do with the paragraph, however, depending on another passage, it can be arguable that Ms. Slades friend is the minor character. I prefer you say the manager.
C. It demonstrates how miserable she felt.
Zitkala-Sa was put through many tortures, based on this excerpt. It is clear that she was taken away from her mother young, and that her captors did terrible things to her like tie her to a chair and cut off one of her braids. If she was treated like this, it serves as an example for how the rest of her people were probably also treated.