Norma Deloris Egstrom, born in Jamestown, N.D., on May 26, 1920, had a reason to leave her given name behind. After her mother’s death, when Egstrom was 4 years old, her alcoholic father and cruel stepmother made life at home difficult. When a local radio host suggested she go by Peggy Lee instead, the girl formerly known as Norma began a new and sunnier chapter. LIFE profiled Lee in 1948, when she was 27 and already half a decade into her career as a singer.