Coming of Age story of a first generation latina Ana García (America Ferrera) who struggles to balance her family's culture where she is expected to work in her sister's dress warehouse, find a husband and have children and forget her dreams of a college education. However, one of her high-school teachers tries to convince her parents to give her an opportunity and send her to university. Her mother Carmen (Lupe Ontiveros) refuses point blank. She alleges that her other sister, Estela (Ingrid Oliu), is a spinster and she'll never marry, so it's Ana's task to give her grandchildren.
Ana starts working at Estela's dress factory. First, she doesn't make much of an effort. The work is hard, but Estela is nice to all her employees, and especially Pancha and Rosali (Soledad St Hilaire and Lourdes Pérez) are good-fun hard-working ladies. Ana is in charge of ironing the dresses and putting them onto hangers after they had already been made. She sweats a lot so she decides to take away her t-shirt and work in her bra and snickers. Almost all the workers followsuit in a hilarious moment, while Carmen, always the spoilssport, almost loses it.
Ana realises that Estela'll sell her dresses cheaply while on the mall they will be very expensive. It comes a moment when the new collection is not finished, and Estela cannot afford the pay the rent of her workshop. They go to talk to their business partner at the mall, Mrs Glass (Marlene Forte) who refuses to give them some money in advance. Mrs Glass is a business woman of Latin origin who offered the job to Estela's factory to help her out in the first place, but has to be tough if she wants to succeed herself. Finally, it's Ana who asks her father (Jorge Cervera Jr) for the money, saying that she could have never imagined Estela worked so hard.
Ana has a high-school love interest who seems to be attached to her even when school is over, Jimmy (Brian Sites). They are not supposed to ever meet, but Ana and her grandfather (Felipe de Alba) help each other. They are supposed to go for a stroll together, but when they turn the corner, each goes separate ways. Ana goes to meet with Jimmy.
Estela finally makes it: she finishes her collection, she sells it to Mrs Glass on time and she can give the lent back. She also makes a special dress for Ana: a red party-dress which she is gorgeous in.
Ana and Jimmy meet several times, and they look very much in love. Ana and Jimmy kiss, and on another occasion they have sex together. In spite of Jimmy's hot looks, it's Ana who doesn't feel really attached to their relationship. Sex is something which will make her more mature, and she really likes Jimmy, but she's not romantically attached to him.
So Ana has decided to give her final step towards independece: she has got a grant to Columbia University in New York. She tells her family when it's all decided in her mind, but this time, to Ana's surprise, her father really backs her up. Her mother gets in a frenzy of hers, blaming the saints, and when Ana moves out, Carmen locks herself in her own room, refusing to say "goodbye" or "good luck" to Ana. Ana's father is the one who will taker her to the airport in his rundown truck. Ana will leave sadly, without Carmen's blessings. That marks Ana's refusal to comply withy her role in Latin society as a submissive woman. Ana leaves Jimmy without a second thought as well. The rest of the family says goodbye to her, and especially Estela agrees with Ana's decision.
The last scene is Ana walking down a New York avenue on her own, with a new more-urban kind of look, self-assured and contented with her life.