Mrs McArdy was foaled in 1974, by Tribal Chief out of Hanina. A bay mare with a large white star she was bred by Lord Grimthorpe. She was purchased at his dispersal sale and put into training here at Sheriff Hutton, and sold to Edith Kettlewell.
As a two year old Mrs McArdy was a four times winner (at Doncaster, Thirsk, Redcar and Newcastle) before proving herself at the very top level as a three year old.
In 1977 she had shown huge improvement on the gallops and her first win of 1977 was the Tote Free Handicap. A fortnight later she won the fillies classic the 1000 Guineas at Newmarket, defeating Freeze the Secret. She went onto win the Fen Ditton Stakes at Newmarket conceding weight to colts and older horses. Later the same season she took the Strensall Stakes at York.
At the end of her three-year-old campaign she was sold at Newmarket's December Sales for 154,000gns, which was then a record for a horse in training, and sent to the United States but failed to win.
Mrs McArdy then returned to stand as a broodmare in Europe, her progeny including four winners. She then stood in Japan, and died at Taiki Farm in 1991 aged seventeen.