Helen Aitchison was the eldest daughter of a Sunderland shipbuilder and was one of four tennis-playing sisters. Helen, along with siblings Alice, Kathleen and Sibyl were four of the six members of the Durham team that beat a strong Middlesex team, containing Dorothea Lambert Chambers, 5-4 in the final of the Women’s County Championship at Newcastle in 1907. Two years later, Helen won the All-England Ladies Doubles championship at Buxton when she and partner Agnes Tuckey came from one set down to beat Maud Garfit and Hilda Lane. This is regarded as an unofficial Wimbledon title, but she did make her All-England début that same year, 1909, and reached the singles quarter-final before retiring injured against the eventual champion, Dora Boothby. She managed to reach the Wimbledon semi-final three times but all ended in defeat; by Edith Hannam in 1911, Dorothea Lambert Chambers in 1913 and Elizabeth Ryan of the United States in 1914.
Helen won a silver medal in the indoor mixed doubles event at the 1912 Olympics with Henry Roper Barrett but lost to fellow Britons Charles Dixon and Helen Hannam after winning the first set. She made up for that disappointment the following year when she beat the four-times French champion Kate Gillou in straight sets to win the World Covered Court championship at Stockholm. Helen married John Leisk in 1914 and continued playing under her married name and in 1922 was runner-up in the Welsh championship and also competed at Roehampton and, for the last time, at Wimbledon, where she reached the ladies doubles semi-final.
Great Britain