Born in Newlyn In 1886, and married to Albert Owen Jewels who died in World War One Mary Jewels preferred to be known as a natural painter rather than primitive or naïve. She mainly painted in oils, her subjects being landscapes, portraits, fishing and harbour scenes. She was a close friend of Dod Procter and her sister, Cordelia was married to the sculptor Frank Dobson.Her subjects remained truly Cornish, as she did not travel further afield.
Never having any formal training, Jewels's introduction to painting came in 1915 when she was given a blank canvas and paints by Cedric Morris and told to "cover it by evening". She considered herself to be a Newlyn painter, though little interest was shown in her work and St Ives was more welcoming. She first exhibited in London in 1928, persuaded to do so by Augustus John who was a family friend.
Having lived to such a great age she was involved with both the early and later Newlyn school of painters and a Solo exhibition of her work was held in Newlyn 1977, the same year in which she died.