Her best singles performance at a Grand Slam tournament was reaching the semifinal of the 1940 U.S. Championships in which she was defeated in three sets by Helen Jacobs.

[5] In July 1931 Hardwick was the runner-up at the singles event of the Canadian Championships after she had to default in the final against compatriot Evelyn Dearman.

[12] In November 1940 Hardwick turned professional, in part to improve her family's financial situation during the war, and she made her debut on 7 January 1941 against Alice Marble in front of a crowd of almost 12,000 at the Madison Square Garden.

[13] The match, which she lost in two close sets, was the first on a transcontinental tour in the United States with a professional group that also included Don Budge and Bill Tilden.

[17] In January 1943 she married Charles Hare, a British tennis player and referee whom she met in the United States.