Sofia is an inquisitive 14-year-old Mexican American girl growing up in a close-knit Texas barrio. She values her family's storytelling traditions, religious rituals, and cultural celebrations, though she sometimes questions how they fit with her personal ambitions. A talented student and soccer player, she faces a major life choice when offered a scholarship to an elite boarding school in Austin. She balances her deep love for her family with her desire for higher education.

Sofia's mother is a traditional woman who acts as a fierce protector of her family and their Catholic faith. Described by Doña Clara as possessing the kicking spirit of a mule, she enforces rules and manners with stern love. She values the concept of the "comadre" above all else and worries about how modern opportunities might pull her daughter away from their cultural roots.

Papa is a quiet, creative man who anchors Sofia's understanding of their Mexican American heritage. Rather than overt religious instruction, he imparts wisdom through shared silence, playing the guitar, and the weekly ritual of cleaning pinto beans. He recognizes an introverted dreamer quality in Sofia, gently guiding her to honor their community while encouraging her individual aspirations.

Lucy is Sofia's sweet, younger sister who easily embraces the traditional expectations of their barrio. Unlike Sofia's tomboyish nature, Lucy looks forward to her quinceañera, loves dresses, and possesses a tender spirit. She acts as an emotional anchor for the family, readily showing her devotion to their shared Catholic rituals and eagerly participating in holiday preparations.

Berta is Sofia's cousin and a study in contrasts to Sofia's academic personality. She cares deeply about makeup, romance, and planning her elaborate quinceañera. Initially at odds with Sofia over their differences in goals, Berta eventually teaches Sofia the true meaning of being a comadre by making dresses from secondhand sheets to support Sofia's boarding school dreams.

Doña Clara is an elderly, revered storyteller within the barrio. She visits local families carrying a burlap sack filled with artifacts, using them to weave tales that connect listeners to their ancestral lineage. She introduces Sofia to the concept of the tequila worm, eating it from a mescal bottle to cure her homesickness as she moves from house to house.

Brooke is Sofia's wealthy roommate at the prestigious Austin boarding school. Despite coming from an entirely different economic and religious background, she lacks the prejudice shown by other students. Brooke respects Sofia's home altar and cultural artifacts, providing Sofia with an unexpected ally and proving that true comadres can come from outside the barrio.

Tia Petra is Sofia's godmother, a woman who takes her spiritual responsibilities seriously. She keeps her house immaculate, famously wrapping her furniture in plastic rolls to preserve it. She requires Sofia to earn her blessing for boarding school by promising to write weekly, emphasizing that education includes spiritual growth and personal happiness.

Tia Belia is Berta's mother and a seasoned curandera (healer) in the barrio. The community calls upon her to cure ailments ranging from the evil eye to unexplained illnesses. She holds a respected position among Mama's comadres and uses traditional methods, such as sweeping a broom over the afflicted, to restore health.

Terry is a wealthy student at St. Luke's Episcopal School who immediately targets Sofia. Driven by Ivy League ambitions and deeply ingrained prejudice, she openly mocks Sofia's Mexican American heritage, her Catholic faith, and her scholarship status. She represents the overt racism Sofia must confront in the privileged world outside her barrio.

Marcos is a fellow student from Sofia's town who also wins a scholarship to the elite boarding school. Finding himself in the boys' dormitory across campus, he shares Sofia's culture shock and homesickness. The two bond over their shared background, providing each other with mutual understanding in an intimidating new environment.

Coach Clarke is the physical education teacher at Sofia's local middle school. When Sofia is mocked for eating bean tacos, the coach invites Sofia to sit with her, trading her own bland sandwiches for Sofia's food. She empowers Sofia to fight back against bullies by excelling in academics and sports, rather than resorting to physical retaliation.

Mr. Thomas is the school counselor at Sofia's middle school. Recognizing Sofia's straight As and hard work, he recommends her for a private scholarship funded by a wealthy doctor, setting her journey to St. Luke's in motion.

Noe is Berta's brother and Sofia's cousin. He participates in family events and holiday gatherings, representing the younger generation of the extended family in the barrio.

Doña Virginia is one of Mama's closest comadres. When she falls ill, she relies on her community and her home altar, decorated with marigolds, salt, and saints, demonstrating the strong spiritual practices of the neighborhood elders.