Espín was married to Raúl Castro, the former First Secretary of the Communist Party of Cuba, who is the brother to former First Secretary Fidel Castro. Their wedding took place in 1959, only weeks after the 26th of July Movement had successfully overthrown dictator Fulgencio Batista. She had four children (Deborah, Mariela, Nilsa, and Alejandro Castro Espín) and eight grandchildren. Her daughter, Mariela Castro, currently heads the Cuban National Center for Sex Education, and her son, Alejandro Castro Espín, is a Colonel in the Ministry of Interior.