Elizabeth Acevedo's novel in verses, The Poet X, is not divided into chapters exactly; the novel is divided into three parts, and each part is subdivided by dates. This answer will interpret the question's use of the word "chapter" as "part."
In the third and final part of The Poet X, which is titled "The Voice of One Crying in the Wilderness," Xiomara tries to carry on going to school and dealing with her home life without Aman. This part takes place during the weeks right before Thanksgiving to early February, when the poetry slam takes place; throughout this time, Xiomara writes poetry about her feelings and her conflicts with her mother, all the while honing her craft. Eventually she feels ready to compete in the city-wide poetry slam, thanks to the support of the poetry club, led by Ms. Galiano, her English teacher, and the encouragement of Caridad and Xavier. The part ends with a truce amongst Xiomara and her immediate family members, and she is reunited with Aman, who appears to have been accepted by her parents, though they don't refer to him as her boyfriend in an official way.