The reader can really feel the sense of despair felt when the author's sister left her alone, and when the former attempted to flee the school only to be trapped by the bars of the gate. Furthermore, the author did a fairly credible job of slowly displaying her signs of relief at first finding similar Spanish speakers, and then eventually finding comfort and ease in the new school. The beginning of the narrative seemed to be a little prolonged, and did not appear to be as necessary as the anecdote about being at the school for the first time. Of course, the author was simply describing the beginning of her first day of school. However, the fighting for the bathroom and the changing of clothes, although detailed, actually seemed to detract a little from the shock of the author being at a new school in a new country....

Ideally, this introductory portion to this chapter should be minimized into a paragraph or two. The way it stands right now the reader is left wondering what the point of the reference to the fishes, and then the bathroom, is for. By shortening this section of the chapter, the memoir would move better and be more interesting for readers.
It was nice how the author contrasted her new school with her former school. The fact that the author chose to include details about her daydreams about her friends and classmates at her former institution of education helped to contrast the extreme strangeness of being at the new place. Moreover, the description of the sizes of the schools, with the new school being considerably bigger, helped to underscore the sense of isolation and loneliness the author felt there.