Lilian Medland was born in North Finchley, London, the daughter of a wealthy naturalist and big game hunter. She showed a love of animals and talent for drawing from an early age. While studying to be a nurse at Guy's Hospital she met the surgeon and ornithologist Charles Stonham, and between 1906 and 1911 she completed 318 monochrome plates to illustrate his five-volume 'The Birds of the British Islands'. In 1911 she was invited to illustrate a revised edition of William Yarrell’s 'A History of British Birds', an edition that was never completed.
In 1907 Medland had contracted diphtheria which left her almost completely deaf. Nevertheless, she continued nursing and painting. By 1913 she was working at the British Museum as secretary to the ornithologist and collector Gregory Mathews, where she met the conchologist and ornithologist Tom Iredale. They went on to marry in 1923 and emigrated to Australia. Medland contributed illustrations to Mathews's twelve-volume Birds of Australia (1910–27) and Mathews and Iredale's 'Manual of the Birds of Australia' (1921). Additionally she illustrated the plates for her husband's books 'Birds of Paradise and Bower Birds' (1950) and 'Birds of New Guinea' (1956), and was commissioned to create a stamp for Norfolk Island.
