Hockin joined the suffragette movement in 1912. In 1913, after arson attacks on the Roehampton Golf Club and on a house at Walton Heath belonging to Lloyd George, suspected to be suffragette-related, Hockin was arrested, convicted and handed a four-month sentence. Her flat was said to contain stones, kerosene and false car number plates. Unusually she agreed not to go on hunger strike if she was allowed to paint. She was treated as a "Category One prisoner", and it was said by a fellow prisoner, Margaret Scott, that she carved the chair in her cell.
The National Portrait Gallery has a picture of her by the Criminal Record Office, and two pages of picture called "Surveillance Photograph of Militant Suffragettes", also by the Criminal Record Office, which includes her. Her picture was taken from a concealed car in the prisoners' exercise yard using an 11 inch powerful lens which had been purchased by the Home Office. The secret pictures were required because the suffragettes would distort their faces when conventional mug shots were being taken. The Home Office was worried by the impact of their arson and vandal attacks and they were closing art gallerys.
Hockin was a Land Girl during the Great War, and later wrote Two Girls on the Land: Wartime on a Dartmoor Farm, which was published in 1918. In 1922 she married John Leared who trained polo ponies in Cheltenham. They had two sons.
- Elizabeth Crawford (1999). The Women's Suffrage Movement: A Reference Guide 1866-1928. London: UCL Press. pp. 287–288. ISBN 9781841420318.
- Bonnie White (2014). The Women's Land Army in First World War Britain. Basingstoke: Palgrave Macmillan. p. 122. ISBN 9781137363916.
- "Olive Leared (née Hockin) - Person - National Portrait Gallery". Npg.org.uk. Retrieved 2016-07-30.
- "Strong Willed & Courageous … Margaret Schencke – A Woman of Fortitude". Women's History Network. 2015-02-08. Retrieved 2018-05-05.
- Simon Schama (16 September 2015). The Face of Britain: The Nation through Its Portraits. Penguin Books Limited. pp. 578–. ISBN 978-0-241-96371-5.