Hedwick Wilhelmina McDonald's greatest achievement as a racehorse trainer does not appear in record books; nor does her real name. She trained the winner of the 1938 Melbourne Cup, but because women were not permitted to be professional trainers in Australia at the time, her husband temporarily took over the role. As for her name, most of her life she was known simply as 'Granny'.
She was born on 28 April 1893 at Hastings, New Zealand, the elder of twin daughters of Hedwick Wilhelmina Douglass and her husband, John Maher, a racehorse trainer. Her mother died two days after she was born, and in 1895 her father married Marion Ann Spicer. Granny's twin sister, Hilda Emma, was known as 'Darkie'; their elder sister, Ethel, as 'Teeny'. Nobody who knew them in later life had any idea of their real names.
Granny Maher's affinity with horses was evident from an early age. She won her first prize in the show-ring at five, and several years later was winning against women. From the age of 11 she helped exercise her father's thoroughbred charges. The family lived for a time in Palmerston North and Wanganui, where the girls attended convent schools, before returning to Hastings. Among John Maher's patrons was Charles Vallance, a prominent Wairarapa farmer and horseman. When Granny set up as a trainer on her own account, several of Vallance's horses, which she had helped to prepare, formed her first stable. It is likely that she initially operated from her father's Hastings property.
In 1924 Granny Maher became New Zealand's first female professional racehorse trainer. Probably because of her background, she faced no apparent opposition from the male-dominated racing hierarchy. Nor did the press make any comment at the time. She proved her ability by training 17 winners in the 1925–26 season; the leading tally was only 36, and she did better than many long-established trainers. In July 1926 the racing reporter for the Weekly Press acknowledged the 'Lady Trainer's Success'. He described Maher as 'a most accomplished horsewoman, physically admirably equipped, possessed of a woman's conscience and a man's resolution, free from mannerism and affectation'. He concluded, 'I doubt if there is another of her sex in the Empire so well qualified to follow the career she has chosen for herself.'
In 1928 Granny moved to Palmerston North, where she established her own stables in Milford Street (now Pitama Road). This was to be her home for the rest of her life. On 30 January 1929, at Palmerston North, she married Allan William McDonald, a well-known steeplechase jockey. The contrast between the pair was striking. Allan was noted for his quiet, gentle nature, and did not smoke, drink or swear; Granny did all three, and her manner seemed fearsome to a young relative.
With the patronage of several eminent owners, Granny McDonald became one of New Zealand's most successful racehorse trainers. During the 1930s horses from her stable won 196 races; only three trainers produced more winners during the decade. She was successful in almost every category of horse-racing: two-year-olds, classic three-year-olds, stayers, sprinters and jumpers. Allan rode most of his wife's winning steeplechasers, helping him to establish a New Zealand record of 297 jumps victories. Although Allan and Granny worked together, there was never any doubt who was boss of the stables. When Catalogue won the 1938 Melbourne Cup, congratulations were directed at Granny, not Allan. Among the sheaf of telegrams was one from the prime minister, Michael Joseph Savage.
The Melbourne Cup win was the peak of Granny's career. A few years later her health deteriorated as she became increasingly dependent on alcohol. Allan took over the stables, but he was not his wife's equal as a trainer. The household had long been run by Granny's sister Darkie, who stayed on to keep house after her sister's death. After suffering a stroke Granny McDonald died at Palmerston North on 5 October 1959. She was survived by Allan; they had no children.