Harrison was born in London, the daughter of the author Stephen Winsten and the artist Clara Birnberg.

[2] As a Quaker and as a conscientious objector during the Second World War (thereby following the stand of her father in the First World War), she served in the Friends Ambulance Unit, first in Hackney, London, and then with displaced persons in Schleswig-Holstein and Bochum in Germany.

[3] In 1964, Harrison published Animal Machines, which describes intensive poultry and livestock farming.

[4][5] The book prompted the British government to appoint a committee chaired by Francis Brambell to investigate the welfare of farm animals.

[6] Harrison's book was published in seven countries and was the inspiration for the European Convention for the Protection of Animals Kept for Farming Purposes.