In Latino culture, the quinceañera is a customary ceremony to commemorate a girl's 15th birthday. More importantly, it signifies the transition into womanhood. The amount of fuss and pomp (read: money) over this event is taken to be indicative of the family's economic status, and the similarities to weddings don't stop there—the young woman of the hour almost always wears a big, fluffy, white, virginal dress.
You can understand, then, the monument of mess that 14-year-old Magdalena (Emily Rios), the central character of co-writers and directors Richard Glatzer and Wash Westmoreland's Quinceañera, is in when it's discovered that she's pregnant—just as preparations are starting to be made for her quinceañera.
Set in the Echo Park section of Los Angeles, an area undergoing rapid gentrification, Quinceañera follows Magdalena's ousting from her parents' house to live with her great grand uncle, Tío Tomás (Chalo González). Tomás has already taken in her cousin, Carlos (Jesse Garcia), similarly ostracized from the family because of his gang affiliations, petty crimes, and homosexuality.
The film is a slow-building drama, inspired by the British "kitchen sink" dramas of the early '60s, and its success is surely due to the relationship the filmmakers have to their subject. Themselves a gay couple living in Echo Park, Glatzer and Westmoreland are examples of what they themselves have called "the frontline of gentrification—gays and artists." A parallel gay couple plays a pivotal role in the script, but are ultimately the film's least likeable forces—causing one to wonder if Quinceañera was born partly out of guilt, a consolation to a community that Glatzer and Westmoreland are contributing to the disruption of. But because the film feels so purely and honestly motivated, that twist in perspective is more of a "because of" than a "despite" in regards to Quinceañera's triumph.