She married Ricardo Guerra Tejada, a professor of philosophy, in 1958. The birth in 1961 of their son Gabriel Guerra Castellanos (now a political scientist) was an important moment in Castellanos’ life; prior to his birth, she suffered from depression after several miscarriages. However, she and Guerra divorced after thirteen years of marriage, Guerra having been unfaithful to Castellanos. Her own personal life was marked by her difficult marriage and continuous depression, but she dedicated a large part of her work and energy to defending women's rights, for which she is remembered as a symbol of Latin American feminism.
In 1958, she received the Chiapas Award, for Balún Canán, and two years after the Xavier Villaurrutia Award, for Ciudad Real. Among other subsequent awards, the Sor Juana Inés de la Cruz Award (1962), the Carlos Trouyet Award of Letters (1967) and the Elías Sourasky Award of Letters (1972).