Margaret Burton Horan was born in Sydney, daughter of Dr John Burton Cleland CBE and his wife, Dora Isabel (nee Paton.) Margaret was a handsome and highly intelligent unassuming woman with a caring personality.

Margaret's family background was notably distinguished. Her father trained at the London School of Tropical Medicine from 1905 where he studied under Robert Muir in microbiology. In 1920 he was appointed to the Marks foundation Chair of Pathology and Bacteriology in the University of Adelaide. He was a recognised world authority on fungi and showed Australian X disease (MVE) was transmitted virally and dengue fever was transmitted by Aedes aegypti.

Margaret's siblings had distinguished careers. Elizabeth was a zoologist, William a pioneer cardiothoracic surgeon, Barbara a mathematician and John a biochemist and anthropologist.

Margaret married Dr John Horan (qv) in 1940. They had met on their way to London in 1936 for postgraduate studies. John Horan was a pioneer physician in gastroenterology, a foundation Fellow of the RACP and a senior physician consultant and Dean at St Vincent's Hospital Melbourne. They had four children.

Margaret started school at Arden House in Sydney, aged seven, having previously been taught by a governess. When the family moved to Adelaide she attended Walford House School (Anglican) with her sister Elizabeth. She left school in 1926 and won the Thornber Bursary, the first time it was awarded. She proceeded to Adelaide University as a science student but transferred to medicine and graduated in 1931. She was RMO at Adelaide Hospital in 1933 and the Children's Hospital in 1934, then registrar in 1935 at the Adelaide Hospital. Following the customs of the time she voyaged to the United Kingdom in 1936 and passed the MRCP (London) that year, the first South Australian medical woman to do so.

Margaret's preference for paediatric involvement stemmed from feelings of happiness and hope at the Adelaide Children's Hospital. After gaining her MRCP, an introduction to Sir Leonard Parsons in Birmingham secured a research assistant post from 1937 to 1939 followed by a professorial house physician appointment in 1939. During this time she made a study of normal haemoglobin levels and red cell values in the first year of life.

With the outbreak of war in 1939, the Children's Hospital in Birmingham discharged all patients and she returned to Adelaide by ship, only later learning that German raiders were prowling the Atlantic. Following the enlistment of Dr Richard Pellew, Adelaide Children's Hospital Medical Superintendent, Margaret took his place from 1940 to 1942. During this time she was closely involved in care and teaching.

The rearing of her family took over between 1944 and 1954 when she was appointed staff specialist to John Colebatch's outpatient clinic in the Carlton site of Royal Chidren's Hospital Melbourne. This resulted in later engagement in the haematology sub speciality when conditions such as thalassaemia, haemophilia and leukaemia were presenting challenges. She retired from this post in 1973. During the period 1960 to 1973 she ran her own clinic for children at the Queen Victoria Hospital as honorary specialist to out-patients. She also put up her plate for internal medicine in Collins St with John, as well as at the Mercy Hospital, East Melbourne. Her private practice was not extensive but she is quoted at being pleased to be involved at the beginning of modern paediatrics and its sub speciality haematology.

She was elected FRACP in 1964, not only one of the husband-wife collegial combinations but also the possibly unique combination of father and husband both being foundation RACP fellows. Memberships included the Australian Paediatric Association, the later Australian College of Paediatrics and the Haematology Society of Australia.

In retirement Margaret's range of interests outside medicine included the Lyceum Club, the National Trust and the National Gallery Society. The couple were interested in gardening and racing. Margaret was a regular visitor to assist at Mount Royal Elderly Centre, Melbourne.

Dr Margaret Horan's life is reflective of changes in society and medicine over the last 130 years. Her contributions to the development of paediatric haematology are acknowledged.