Mrs McArdy was foaled in 1974, a bay filly with a white star 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. She was actually sold to Edith's husband as a present for his wife. The couple ran a motel in Wensleydale.
Mrs McArdy made her debut at York on 11th June 1976, finishing unplaced in the Dick Turpin 2yo Fillies' Stakes. It was on her fourth racecourse outing that she would win for the first time. Ridden by Neil Crowther she took the Westgate Stakes for two year old fillies at Newcastle at odds of 12/1. She followed up in the Barton Cottage Nursery at Thirsk, this time sent off 13/8 favourite and winning by a length. She would complete a four timer, courtesy of wins at Doncaster and Redcar. Neil Crowther rode her in all four wins.
Mrs McArdy's three year old campaign began at Doncaster, where she finished seventh behind stablemate Tudor Jig. However, she would make amends next time out by taking the Tote Free Handicap at Newmarket, sent off as the 8-1 joint favourite. She raced up the middle of the course and hit the front two furlongs out. The horses were in two groups, with the horses on the stands side having little chance. She win by two and a half lengths. Mrs McArdy was providing the second leg of an unusual double, as earlier in the week Tudor Jig had won the Northern Free Handicap for the yard. The horses had worked together and on the gallops Mrs McArdy could certainly keep up with Tudor Jig. Once Tudor Jig obliged it was clear that Mrs McArdy had every chance, and she was backed in from 20-1 to 8-1 for the Newmarket race.
After the Free Handicap she was priced up at 25/1 for the 1000 Guineas and two weeks later she would indeed line up at Newmarket for the fillies' classic.
Eddie Hide rode her in the Guineas and she was up against the best three year old fillies. Cloonlara was the horse to beat and started 6/4 favourite. In the race Mrs McArdy hit the front two furlongs out and the result was never in doubt thereafter, passing the post two lengths ahead of Freeze The Secret. After the race jockey Eddie Hide said "We were never going to get beaten. I thought Lester would ride Cloonlara from behind so when he jumped off I just tracked him. I stayed there until going down the hill and then went on to win."
It was third time lucky in a classic for the yard, with Pal's Passage having contested the 2,000 guineas several years back and Tudor Jig running unplaced in the 2,000 Guineas of 1977. Tudor Jig had the ground against him and also had no luck in running. Tudor Jig was a far better horse than Mrs McArdy but unless the ground was soft, or even better heavy, he was not going to be at his best.
After the race Mrs McArdy was given a 10/1 quote for the Oaks but on breeding she would never be expected to get a mile and a half. In the event she didn't stay and finished second last, but she soon made amends at Newmarket when winning the Fen Ditton Stakes, conceding weight to colts and older horses. She finished sixth at Glorious Goodwood in the Sussex Stakes to Artaius (Lester Piggott).
Mrs McArdy's final victory came on her home course of York. On 31st August she won the four runner Strensall Stakes ridden by Eddie Hide. Sent off the even money favourite, she defeated Be Easy buy a length and a half. The filly could not follow up and in her next race finished third in the Sanyo Stakes at Doncaster where she had been the 10/11 favourite.
Doncaster would prove to be her final race. 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.