Mary Thornycroft studied under her father, John Francis, and was regarded as a child prodigy. In 1840 she married the sculptor Thomas Thornycroft who was assisting her father in his studio at the time. She made her debut at the Royal Academy in 1835 with the genre figure 'The Young Woodcutter'. She travelled to Rome 1842-1843 with her husband. On the recommendation of John Gibson, Queen Victoria commissioned her to sculpt her daughters as the four seasons and she followed this with many individual portrait busts of the Royal Family, some of which are held in Royal collections at Buckingham Palace and Osborne House.
Rupert Gunnis notes a model of 'The Skipping Rope' at Osborne House (Dictionary of British Sculptors 1660-1851, London, 1953). This was a popular model and was copied by Minton in Parian Ware. An engraving was published in the Art Journal in 1861 and another in the Illustrated London News of 10th August 1867.