At the beginning of May, Isabel announces that she is in the running for "Queen of the May" at her school. Esperanza encourages Isabel's aspirations because the younger girl has perfect grades. However, once Isabel is out of earshot, Josefina explains that only American girls with blond hair and blue eyes win the title. Despite her academic achievements, Isabel will never be elected because of her ethnicity.
A week later, Isabel is still obsessed with becoming the Queen of the May. She cheerfully announces that someone is building a new camp for the workers from Oklahoma where there will be a pool. However, Mexican workers will only be allowed to swim one day per week. Hortensia adds that the time for Mexicans too swim is on Friday afternoons, right before the pool is cleaned on Saturday mornings (based on the stereotype that the Mexicans are dirtier than the other migrant workers).
Miguel returns home, covered in dirt, and explains that his job as a mechanic went to one of the inexperienced workers from Oklahoma simply because the "Okie" was willing to accept a lower wage. Esperanza becomes outraged when Miguel tells them that he has agreed to dig ditches instead. Miguel tries to reason with Esperanza, but she runs away from their cabin.
Esperanza is angry. She asks Miguel if he thinks life is better for him in the United States. Miguel defends their decision to move to California because at least there is a possibility for upward mobility. Esperanza shouts at him, telling him that even in the United States, he is a second-class citizen. Miguel retorts by telling Esperanza to stop thinking about herself the "queen" she had been back in Mexico.
The following morning, Miguel is gone. Hortensia says that he has gone to find railroad work up in Northern California. However, Esperanza feels responsible for his departure. To keep herself from thinking about Miguel, Esperanza throws herself into her work.
Later, Isabel returns and tells Esperanza that she did not win Queen of the May. She is devastated and complains that life is not fair. In order to cheer her up, Esperanza gives Isabel her prized doll, explaining that Queen of the May title only lasts for a month but the doll will keep her happy much longer.
Then, Esperanza receives the good news that Mama is better and can return home within the week. Everyone readies the house for Mama’s return and Esperanza is elated to have Mama back home after five months in the hospital. She is especially excited to show Mama all of the money she has made from working. However, when she looks in her valise, Esperanza discovers that all of her money orders are missing.
Esperanza has been living in an all-Mexican camp and working with only Mexicans for several months. Her encounters with American racism are limited to the immigration raid and the fact that they have to shop at Mr. Yakota’s store. Esperanza feels angry when Isabel loses the Queen of the May title because she knows that Isabel never had a chance. Esperanza's anger increases when she learns that Mexicans can swim in the new pool the day before it is cleaned because everyone assumes that they are dirtier than the other migrant workers.
To help make Isabel feel better after losing out on being Queen of the May, Esperanza gifts the younger girl her precious doll. She explains that the doll is permanent and is worth more than a silly title. In this exchange between Esperanza and Isabel, it becomes apparent how much Esperanza has learned since arriving in the United States. She is able to feel compassion for Isabel and give up her most prized possession because she knows that it will be of more value to the other girl. She has also finally learned how to let go of her past life and forge ahead into her future.
Additionally - for most of the novel, Isabel (who is younger) has behaved as though she is older than Esperanza. She has been Esperanza's guide - teaching her how to do chores and take care of babies. Now, it is Esperanza's turn to be the big sister. She sacrifices her most prized possession to make Isabel smile - and less than a year earlier, she would not even let anyone else touch the doll.
Esperanza also has to confront social class disparity from a new perspective. When Miguel and Esperanza argue, it is clear that the difference in their social classes in Mexico have not simply disappeared because they are in another country. Despite her maturation, Esperanza is still deeply frustrated with their current situation and cannot tolerate the injustices that are unfolding around her. Even though she is upset on Miguel's behalf, her outrage comes out as an angry attack against him.