Powell was born on August 22, 1868 in Peru, Illinois, United States. She was the daughter of William Bramwell Powell and Minnie Paul. Her father was an author and school superintendent; her uncle, Maj. John Wesley Powell, was the distinguished ethnologist and pioneer explorer of the Grand Canyon. Her mother was of German-Hungarian ancestry and was an amateur composer, and the daughter showed musical talent at an early age. In 1870 the family moved to Aurora, Illinois.