This chapter is about three sisters who live in the same house, and the narrator, Esperanza, is fascinated by them. While Rachel and Lucy are not the main focus of the chapter, they are significant because they represent the kind of life Esperanza wants to avoid.
It's important to note that Lucy and Rachel aren't the most well-developed characters in the book, but they do contribute to the overall themes of family, gender roles, and the search for identity that are prevalent throughout *The House on Mango Street.*