Symbolism, Imagery, Allegory
For Yolanda and her sisters, the Island (shorthand for the Dominican Republic) isn't just a physical place. It's also an imaginary place. It exists in their heads as a symbol with a double meaning: an idealized paradise of a home where their lives make perfect sense, and it's an oppressive cage. Both ideas are constantly in flux. It's sort of a "can't live with it, can't live without it" kind of scenario.
In the first chapter, for example, Yolanda pines after her homeland like it's the solution to all of her problems. "Let this turn out to be my home," Yolanda wishes when she returns to the D.R. for a visit. She longs to drive out in the country by herself, thinking as she looks at the quaint little campesino cottages, "This is what she has been missing all these years" (1.1.59). And she hungers for guavas, picked fresh from the tree. It's all part of the nostalgic Island getaway package.
But Yoyo didn't always think of the Island with so much nostalgia. As teenagers, she and her sisters think of it as a cage—a really pretty, tropical cage, but a cage nonetheless. It's like a monkey experiment that their sister Carla tells them about:
These baby monkeys were kept in a cage so long, they wouldn't come out when the doors were finally left open. Instead, they stayed inside and poked their arms through the bars for their food, just out of reach. (2.1.149)
That's the trouble with the Island—it's completely inescapable. For the García girls, their family will always tie them to the Island. And being tied to the Island means not being to fully embrace their American identity. It will always be "just out of reach."