Her first job was with a small advertising agency, where she sketched portraits of motion-picture personalities from publicity photographs, She completed several paintings of the country before returning to Sydney to seek employment. She subsequently travelled to
Fiji,
Samoa, and the
Pitcairn Islands in 1953. Sandwith returned to Tonga to teach English at the
Free Church of Tonga, and lived with a Tongan family, during her work to sketch and record the islanders' culture, earning her the name "The Drawing Girl". In 1954, she persuaded
Sālote Tupou III to sit for a portrait, the first of a
queen of Tonga, after a cabinet meeting of
Tongan nobles convened to grant her permission for the painting. Sandwith returned to England in 1955 and lived in London. She decided to train to become a nurse, enrolling at the
Royal Free Hospital from 1956 to 1959. After completing her training, Sandwith worked as a staff nurse at the
St Mary's Hospital between 1962 and 1963. She continued to exhibit her sketches during this period, at the
Royal Society of British Artists, the
Society of Women Artists, and the
Brighton Museum & Art Gallery. Sandwith spent part of 1965 sketching in Canada and also worked as a nurse in
British Columbia. She later returned to London and attained employment as a
health visitor in the
Borough of Newham from 1972 to 1975 and
Redbridge and
Waltham Forest between 1975 and 1979. Sandwith continued to visit unusual places and took up courses in drawing and design and also garnered an interest in etching on copper. She eschewed photography of human subjects as she believed draughtsmanship captured better details and delivered spontaneity. ==Final years and death==