Who is Rafaela Cortez from Tropic of Orange: A Novel and what is their importance?

Rafaela is originally from Culiacan, Mexico. About a decade before the beginning of the novel, she moved north to the United States. Rafaela got into the United States legally because she married a citizen. Since moving to the United States, she helped her husband start a successful janitorial business and studied at a community college. Rafaela also had a son who is two years old at the opening of the novel.