Roberts was born in Decatur, Georgia. Her mother, Betty Lou Motes (nee Bredemus), was a one-time church secretary and real estate agent, and her father, Walter Grady Roberts, was a vacuum cleaner salesman. Roberts's parents, one-time actors and playwrights, met while performing theatrical productions for the armed forces and later co-founded the Atlanta Actors and Writers Workshop in Atlanta, Georgia off Juniper Street in Midtown; the two divorced in 1971. Her mother later married Michael Motes and had a daughter, named Nancy Motes, who was born in 1976. Roberts's father died of cancer when she was ten.