The daughter of James Sheridan Clarke (September 18, 1912 – January 18, 2009), a veteran of World War II, and Edna Clarke, Cheryl was born and raised in Washington, D.C. at the height of the American civil rights movement, one of four sisters and a brother. The family was Catholic, descended from freed slaves who had emigrated to the nation's capitol after the Civil War. Both parents were civil servants and registered Democrats: James Clarke worked for the National Bureau of Standards for 33 years, and was considered to be the "mayor" of their neighborhood in the NW section of Washington. Experiencing Jim Crow segregation first hand in Washington for much of their lives, James and Edna raised their children with a strong sense of social justice and a belief in the importance of political activism.