Character Clues
Character Analysis
Name
Really, this only applies to the character of Yolanda, but since she's the protagonist, her characterization is kinda a big deal. The chapter called "Joe" explores Yolanda's annoyance at the fragmentation of her name into about a zillion nicknames: "Yolanda, nicknamed Yo in Spanish, misunderstood Joe in English, doubled and pronounced like the toy, Yoyo—or when forced to select from a rack of personalized key chains, Joey" (1.4.1).
These associations—of being "misunderstood" or associated with a toy—definitely aren't positive ones. Yolanda seems pretty unhappy with her name, and that reflects her greater unhappiness with her identity. Who is she? What language does she live in? What culture does she belong to?
It's also really significant that one of Yolanda's nicknames is Yo, the Spanish word for "I". As a lot of people have pointed out, Yolanda is probably an alter ego for the author herself. Her nickname, Yo, is definitely evidence in favor of this argument.
Family Life
Ever heard of birth order psychology? It's the theory that a sibling's place in the birth order of the family determines some of her characteristics. Guess what birth order psychology says about oldest children? That they're bossy. Surprised?
Well, Miss Bossypants Carla certainly fits the stereotype of the oldest child. Yolanda complains that Carla "has a tendency to lace all her compliments with calls to self-improvement. [...] Somehow this makes her praise sound like their mother's old 'constructive criticism'" (1.3.159).
Even though Yolanda, Sandi and Fifi don't have personalities that are so much dictated by their order of birth, their identity as one of "the four girls" is central to how they see themselves, and how the rest of their family views them.
Occupation
What does it take to be a good poet? Well, for starters, you have to be sensitive to language. That definitely describes Yolanda, who is so sensitive to language that it even has the power to make her sick. (Don't believe us? Read the chapter called "Joe.") For a while Yolanda starts denying that she's a poet; she starts calling herself a "writer-slash-teacher" and even announces to her family that "she was not a poet anymore" (1.3.36). So sad. When Yolanda feels she's no longer worthy of the title of "poet," she loses a part of her identity.
Carla's gravitation towards psychology means she has a tendency to try to psychoanalyze her family. She also has a tendency to make inside jokes with her analyst husband, and then refuse to explain why they're funny. Sorry, psychologists only! It's pretty annoying.
Mami's career as a stay-at-home mom reflects her belief in traditional gender roles. That's what upper-class moms are supposed to do, right? But when Mami moves to the U.S. and starts exploring a career in real estate, we get the sense that she's finally rebelling against these strict rules about what she can and cannot do. Go Mami!