Born in Hobart 1908, she began studies at the Sydney Art School in 1926 with Julian Ashton and Thea Proctor. After marrying fellow painter and art critic, Paul Haefliger, the pair travel to the UK and the Continent. Between the years 1936 and 1939, Bellette alternates between further studies (Westminster Art School, London and Colarossi's and La Grande Chaumiere, Paris) and travel.

After her return to Australia prior to the outbreak of hostilities, she wins the Sulman Prize twice - in 1942 with 'For whom the Bell Tolls' and in 1944 with 'Iphigenia in Tauris'. During this time she becomes involved in taking a leading role in organising the Sydney Group which provided focus for neo-romantic painters including David Strachan, Justin O'Brien and Francis Lymburner. Bellette and her husband left Australia for Europe in 1957, eventually setting in Majorca, Spain. From that time on she travelled widely, continuing to produce works throughout the 1960's to mid 1970's. Her Majorcan works were exhibited in both Sydney and Melbourne between 1964 and 1976.

She died in 1991 in Majorca.