McDonald was born in Rock Island, Illinois. After studies in Chicago and New York City, at age 15 she entered the Conservatoire de Paris, where she studied with Henriette Renié and Lily Laskine and in 1955 was the first American to win the Premiere Prix de Harpe. Not long thereafter, she placed second in the first International Harp Competition in Israel; in 1970, she returned to the competition as a judge. Around this time she also had an audience with Juliana of the Netherlands following a recital at the Concertgebouw.