Despite being our main character, we never learn the narrator's name. But that doesn't mean we don't know much about her—she is our main character, after all. So let's try to flesh out this nameless leader of ours.
The narrator comes from a family of daughters, but she's the odd girl out because she doesn't fit the feminine expectations her parents have for their lady offspring. Our girl's an outsider primarily because she has big hands (she's even called "bull hands" at a point), making it difficult to do the crochet and embroidery work her sisters do easily. Check out the sisterly dynamics at work:
[…] I always pricked my fingers or knotted my colored threads time and time again while my sisters laughed and called me bull hands with their cute waterlike voices. (2)
So yeah, there's a pretty clear line drawn between our narrator and her sisters. Must be kind of rough to always be the odd (wo)man out, right? It's hard always feeling like you don't belong.
Don't go feeling too sorry for old bull hands, though—she gets her sisters back and then some. Her violent escapades include "keeping a piece of jagged brick in my sock to bash my sisters or anyone who called me bull hands" (2), and "deliver[ing] one last direct shot on Marisela's arm and jump[ing] out of our house, the slam of the screen door burying her cries of anger" (4). In other words, the pain the narrator feels when her sister call her names is returned in the form of physical violence—she's not exactly wilting in a corner while everyone points and laughs.
This characterization of the narrator sets up a big dynamic shift from the beginning to the end of the short story. She starts off a loose cannon, full of vim and vigor (got to love that alliteration). This violent characterization contrasts with the gentle sympathy she shows her grandmother by the end of the story, though, emphasizing both our main girl's ability to change and her complexity.
The narrator has lots of battles with her parents. She isn't obedient and her father doesn't take very kindly to that—in fact, he's pretty dang mean about it. When she won't go to church, for instance, the following happens:
[…] he strategically directed his anger at Amá for her lousy ways of bringing up daughters, being disrespectful and unbelieving, and my older sisters would pull me aside and tell me if I didn't get to mass right this minute, they were all going to kick the holy s*** out of me. (8)
Yikes. Amá (the narrator's name for her mom, which means love) is forced to take the blame when the narrator is disobedient by her dad, Apá, who has everybody heading for the hills when he's mad. The narrator is blamed by her sisters for both their father's anger and their mom's pain, which leaves her feeling like a terrible daughter. Everything seems so tense between our leading lady and her immediate family.
Her relationship with Abuelita, though, is different. It's not that she's an angel for her grandma—she's still sassy and disrespectful, questioning her grandma's home remedies for fever—but she does feel sorry about the impact her actions have on Abuelita, saying at one point: "Regretful that I had let secret questions drop out of my mouth, I couldn't look into her eyes" (3). This difference is probably due to the fact that Abuelita shows love to her granddaughter, unlike Apá. The narrator's harshness feels unwarranted when it's met by softness and love.
When Abuelita dies, the narrator is the only one in the house to deal with the situation. But rather than calling her Amá, who has just left, she takes matters into her own hands. The narrator acts like a responsible adult, first cleaning up the room and then tending to her grandmother's body.
Her final action in the story—carrying her grandmother to the tub and getting into the water alongside her—is when the narrator really starts to seem grown up. She says that Abuelita "was not as heavy as I thought, and when I carried her in my arms, her body fell into a V, and yet my legs were tired, shaky, and I felt as if the distance between the bedroom and bathroom was miles and years away" (15). She is both literally and metaphorically carrying her grandmother on her own, feeling the weight of death both physically and emotionally.
Our narrator is strong enough to carry her grandmother, showing how capable she is. The distance she travels isn't just over physical space, though—when she tells us it feels like "miles and years," we understand that what is happening is the narrator is growing up, leaving childhood behind as she carries her grandmother to the bath. The rebellious girl we initially met is a thing of the past, and as she embraces the responsibility in front of her, the narrator steps into adulthood.