Nursing career
World War I gave to Princess Arthur an opportunity to embrace her vocation of nursing in which she subsequently made a successful career. In 1915 she joined the staff of St. Mary's Hospital, Paddington, as a full-time nurse and worked in this capacity until the armistice. After the war she continued her training at St. Mary's, becoming a state registered nurse in 1919. She was awarded a first prize for a paper on eclampsia. Princess Arthur also practised at Queen Charlotte's Hospital, specialising in gynaecology, where she received a certificate of merit. Throughout these years Princess Arthur increasingly impressed her superiors by her technical skill and practical efficiency.
When her husband was appointed governor-general of the Union of South Africa in 1920, Princess Arthur accompanied him and shared in his popularity. Her tact and friendliness made her friends among the South Africans, who also admired the interest she displayed in hospitals, child welfare, and maternity work throughout the Union. To these subjects she brought her personal knowledge and experience, which enabled her to make effective and valuable suggestions. Despite this, she found life in South Africa restricting.
On her return to London in 1923, Princess Arthur resumed her nursing career at University College Hospital, where she was known as Nurse Marjorie, and subsequently at Charing Cross Hospital. At this time she specialised in surgery and worked as a theatre sister. She performed minor operations herself, such as an amputation of a patient's thumb. Her services to the nursing profession were recognized in July 1925, when she was awarded the badge of the Royal Red Cross by George V.
The outbreak of World War II in 1939 afforded Princess Arthur further scope for her nursing abilities. She refused the offer of a post as matron of a hospital in the country, preferring to become sister-in-charge of the casualty clearing station of the Second British General Hospital set up to treat the troops retreating from Dunkirk. Shortly thereafter, she opened the Fife Nursing Home in Bentinck Street which she personally equipped, financed, and administered as matron for ten years.
Princess Arthur was the first member of the royal family to register as a nurse with the GNC and was president of the Royal British Nurses Association (RBNA) from 1924 through to the NHS planning and launch years (1946–1948). She remained president until her death in 1959. During this time she was actively engaged with national nursing policy, registration issues, Ministry of Health discussions and legislation affecting nurses. The RBNA archives, held at King's College, London, contain her correspondence with government departments and nursing bodies during this period
On 26 April 1943 her only child, Alastair, Duke of Connaught and Strathearn, died unexpectedly (and in ill-defined circumstances) whilst staying at Rideau Hall in Ottawa with his relative the Governor-General of Canada, the Earl of Athlone.