As the younger sister, Nenny is often Esperanza’s responsibility, and though her innocence is a major source of annoyance for Esperanza, it also signals Nenny’s independence. In many ways, Nenny is a pesky little sister. Esperanza must introduce Nenny to her new friends and keep her away from bad influences, such as the Vargas kids. Nenny also has qualities that Esperanza covets, including two names (“Nenny” is short for “Magdalena”), pretty eyes, and shiny, straight hair. Though Nenny can be a nuisance and a tag-a-long, and her actions often embarrass and annoy Esperanza, she frequently demonstrates her independence. When Esperanza, Rachel, and Lucy make up chants about hips, Nenny recites old chants that everyone already knows. Similarly, when Rachel and Lucy describe clouds with creative metaphors, Nenny gives the clouds everyday names such as Jose and Alicia. Nenny’s apparent refusal to be creative embarrasses Esperanza, but her choices suggest she has her own way of surviving on Mango Street.

Nenny and Esperanza don’t seem very much alike, but their differences in age and sociability mask their fundamental similarities. Nenny and Esperanza laugh at the same things, even those things others don’t understand are funny. More important, Nenny and Esperanza are both dreamers. While Esperanza imagines a world outside the barrio, Nenny turns the outside world into the barrio by giving the clouds the same names as her neighbors. By doing so, she enlarges her world and makes it bearable. She turns Mango Street into the center of the universe, a place where she can be happy. Nenny and Esperanza are also very steadfast in their ideas, though Nenny is less likely to go along with the other girls if her views differ. While Esperanza, Lucy, and Rachel bounce ideas off each other, Nenny pursues her own idea. She is not distracted from her dreams, even when the other girls give her dirty looks. Despite Nenny’s similarities to Esperanza, Nenny does not have as much a part in Esperanza’s narrative as other women. Esperanza observes most of the women in her life closely and gives each of them a chapter—except for Nenny. Nenny ultimately recedes from view as Esperanza pursues life beyond Mango Street.