Lillian Mary Pickford was born on 14 August 1902 in Jabalpure, India, where her father was a planter of indigo and tobacco. In the 17th century her forebears had started the Pickford transport service. Her father's cousin, William Pickford, was created Baron Sterndale in 1918, and Sterndale's younger daughter, Mary Ada Pickford, became one of the first women Members of Parliament.
At the age of six, Mary Pickford was left "at home" in England with her aunt. At first, she was taught privately, sharing a governess with a cousin, then in 1914 she was sent to Hamilton House, Tunbridge Wells, and in 1916 to Wycombe Abbey School. In 1921 she went to Bedford College, London University, where she read science, obtaining a first class general honours in 1924. In 1925, she went to University College London and began part-time work in pharmacology with A.J. Clarke and then with E.B. Verney, working on the kidney and the heart-lung preparation. While working part-time, she started clinical studies, and she gained a "conjoint" medical qualification in 1933. In 1935, she was House Physician and Casualty Officer at the Stafford General Infirmary, but when Verney moved to Cambridge University she joined him there as a Research Fellow.
In 1939 she was appointed as a lecturer in the Physiology Department of Edinburgh University; she was promoted to Reader in 1952 and in 1966, became Professor. She gained a DSc in 1951 in Edinburgh and later was given an Honorary DSc by Heriot-Watt University. In 1954 she became a Fellow of the Royal Society of Edinburgh, in 1966 a Fellow of the Royal Society of London and the same year was the first woman to hold a chair in the Edinburgh Medical Faculty. In 1977 she became a Fellow of the Royal College of Physicians of Edinburgh.
Mary Pickford began her career when there were few women doctors and considerable prejudice against women scientists; she was told by Sir Cooper Perry, superintendent of Guy's Hospital and later Principal of London University, that "women are no good at that sort of thing". Her work centred on the role of hormones, and in particular in how the brain, through the posterior pituitary gland, controls the balance of water in the body by the production and secretion of the antidiuretic hormone (vasopressin).
Mary Pickford never married, never had television, loved Turner's paintings and enjoyed the music of Mozart, Beethoven and Britten. She wrote short poems and, in her retirement took up painting; she exhibited annually with "The Edinburgh Women Artists", a group that she had started. She died on the morning of her 100th birthday at Nether Wallop, Hampshire, on 14 August 2002.
- Pickford, Mary (1969) The Central Role of Hormones Oliver and Boyd, Edinburgh
- Obituary The Independent
- Obituary The Telegraph 
- Obituary The Endocrinologist 
- Pickford M (1952)Antidiuretic substances. Pharmacol Rev. 4:254-83. (review)
- Pickford M (1936)The inhibition of water diuresis by pituitary (posterior lobe) extract and its relation to the water load of the body. J Physiol. (first publication) PMID 16994795