Xiomara calls her brother Twin as a confirmation that they are connected, because despite their kindship, they are profoundly dissimilar. Where Xiomara is tall and strong, Twin is short, thin, and weak. Xiomara describes Twin as a genius, and he’s a grade ahead of her in a special school for gifted students. Twin accepts the Catholic faith much more easily than Xiomara does. As much as Xiomara loves her brother, she often doesn't feel that they have any special mental or emotional connections as twins. She also believes that he isn't aware of or empathetic to her struggles, but he does reach out to her—just not always in ways that seem demonstrative or timely enough to Xiomara. 

Because he’s a boy, Twin is the favorite child who doesn’t have to do chores and isn't expected to uphold the same standards of chastity as Xiomara is. However, Twin is secretly gay, something Xiomara has suspected but only confirms when she goes to his school and sees him with his boyfriend, Cody. Twin and Xiomara both know that their parents will never accept Twin’s sexuality, and they keep it a secret even as Cody moves away, and Twin must suffer his heartbreak in silence. Xiomara protects Twin in a way that she can't always protect herself, but he finally stands up to their mother when she burns Xiomara’s poetry notebook.