Sandi is the second-oldest of the four García sisters. At the beginning of the novel, Sandi is sort of a train wreck. She develops an eating disorder and has a "small breakdown" that lands her in a mental hospital. After she's released, Sandi still seems pretty emotionally unstable. She "cries so easily she has to carry Kleenex with her anti-depressants in her purse" (1.3.143).
A lot of the stories Sandi tells in the novel revolve around how pretty she is. As Mami puts it, "The others aren't bad looking, don't get me wrong. But Sandi, Sandi got the fine looks, blue eyes, peaches and ice cream skin, everything going for her!" (1.3.81). Being pretty has its advantages, sure. When Sandi realizes she's pretty for the first time, she's relieved to think how it will help her be more accepted in her new country:
Being pretty, she would not have to go back to where she came from. Pretty spoke both languages. Pretty belonged in this country to spite La Bruja. (2.5.63)
But being so good-looking doesn't keep Sandi from being deeply insecure.
Sandi's looks are tied time and time again to her light complexion, which is "traced back to a great-great grandmother from Sweden at every family gathering" (2.5.63). It definitely draws attention to the way light skin and blond hair is valued amongst the Dominican characters in the book—and how dark skin and hair are regarded as unattractive.
Our favorite Sandi moments are ones in which her vanity and her insecurities are totally absent: like when she doesn't want to be respectful to the drunk American lady who made the moves on her dad, so she sassily uses her doll to say the obligatory "thank you." (2.5.121). That's the spunky Sandi we love.