You probably are referring to Esperanza, the protagonist of The House on Mango Street. She is the source of everything the reader knows in the book, as it's written from her point of view. She is a child when the book starts, but she is teetering on the brink of adolescence. Esperanza is the type of character the reader can trust, as she is very mature for her age. For example, she knows that while her mother tells her the house on Mango Street is only temporary, the family will likely live there for a long time. Esperanza is also a very astute observer of the people around her. For example, she says of Marin that she "is waiting for a car to stop, a star to fall, someone to change her life" (page 27). Esperanza's observations seem far more mature than those of most children. She is also a character that the reader sympathizes with, as she portrays her life with poignancy. When she says at the end of the book that she hope to leave Mango Street one day to live an independent life as a writer, the reader wants her to succeed.