The series of fragments that make up Esperanza's story all would lend themselves very well to a sensory paper, so it would be worth you flicking through and finding one that you like yourself rather than using my ideas. However, I would be tempted to write about the fragment entitled "Hairs."
This has a number of details that help capture the feel, smell and other differences between the hair of Esperanza's family. Note how Esperanza describes her mothers hair as "the warm smell of bread before you bake it." You have the sense of smell, but also the sense of touch in the way that the hair of others is described, the sense of sound with the image of the rain falling and papa snoring in the final line and then the sense of sight in the way that her mother's hair is described as being "like rosettes, like little candy circles all curly and pretty." This would therefore be an excellent section to write a sensory essay on.