A gifted teacher and an educationalist concerned with increasing women's opportunities, Stephanie Grace Young was known and admired beyond the schools in which she taught. She was born on 13 July 1890 at Amberley Rectory, Stroud, Gloucestershire, England, the daughter of an Anglican clergyman, Willoughby Bryan-Brown, and his wife, Grace Margaret Nash. Educated at Laleham School, Eastbourne, Sussex, from 1912 to 1915 she was an undergraduate at Lady Margaret Hall, University of Oxford, where she became a hockey and tennis blue. She qualified for an MA in modern history, but women students at Oxford were not yet entitled to receive degrees. For this she had to wait until she returned to Oxford for the purpose in 1927.
From 1915 to 1916 she was history mistress at Sherborne School for Girls, Dorset. When her help was needed at home, she moved to St Christopher's boys' preparatory school, Eastbourne, where she taught general subjects and coached cricket. Her brother Guy, a chaplain with the New Zealand forces, was killed at Passchendaele (Passendale) in 1917. Marriage to his friend, a New Zealand serviceman, Charles Le Fanu Young, brought Stephanie to Christchurch. She and Charles sailed together on a troop ship after their marriage at Eastbourne on 21 December 1918.
While her husband was in charge of the Lower School at Christ's College Stephanie worked as matron. When Charles, who had been severely gassed in the war, died on 10 February 1921 at the age of 26, she was left with a 14-month-old son, Guy. That year, Stephanie Young began 10 years as history mistress at Christchurch Girls' High School. She was a lively and innovative teacher, training her students in research methods and historical interpretation.
In 1931 Stephanie Young became headmistress of St Margaret's College, Christchurch. While maintaining the Anglican principles of the school's foundation, she was at the forefront of women educationalists who brought girls' education into line with modern thought and practice, as expounded by the Canterbury College professor James Shelley. As well as encouraging scholarship, and the recognition of pupil successes, she instituted open-air classrooms and was active in developing school sport. She introduced cricket, and also founded a car mechanics club for students.
At a time when there was only limited physical education training for women teachers in New Zealand, Stephanie Young established a national training scheme at St Margaret's. Three students a year were accepted for a two-year course directed by an English-trained teacher, Nan King. This exemplified Young's philosophy, which embraced the development of the whole person, spiritual, intellectual and physical.
Liberal in outlook, Stephanie Young emphasised the need for common sense and self-control. To help students develop responsibility and independence she introduced a school council in 1937. She had a reputation for strictness but also for her sense of humour and sympathetic understanding. Tall and dignified in appearance, she had an air of high purpose, like many early women graduates of Oxford University who made careers in education. Her lifelong Christian commitment was an essential aspect of her work, and brought her into contact with the wider community as she organised inter-school meetings through the New Zealand Student Christian Movement. From 1936 to 1952 she served on the Canterbury University College Council.
While she steered the school through the depression, and after she retired in 1949, Stephanie Young was a devoted mother to her son, who made a name in journalism, notably as a contributor to the New Zealand Listener. He died of tuberculosis in 1957, his mother outliving him for 26 years. A central teaching block at St Margaret's is named after her, and a fine portrait by Elizabeth Wallwork at the school perpetuates her memory. She spent a quiet and contemplative but intellectually lively old age at Cashmere, where she died on 6 July 1983.