Rae, a painter, was born in Melbourne on 18 August 1860, youngest of the five children of Thomas Rae, a partner in a soap and candle manufacturing company, and Janet, née Love, formerly of Scotland. She attended the National Gallery Schools in 1877-1887 where Oswald Rose Campbell, her teacher at the School of Design, stressed the importance of anatomy, while George Folingsby in the Painting School instructed her to paint figure subjects in a sober tonal style. Rupert Bunny and John Longstaff were fellow students.
Iso did well and won many prizes. In the students’ exhibition in 1883 the jury made special mention of her work along with that of Jane Sutherland and Amy Vale, and she received further honours in 1884 and 1886. In 1887 she gained third prize for Persuasion, a painting of a Chinese hawker displaying his wares to two girls standing at a kitchen door.
Iso joined the Victorian Academy of Arts and exhibited portraits and figure studies with it in 1881-83.
In August 1887 Iso and her family left Australia and settled in France. She mixed with Australian art students in Paris before making her home in Etaples, a well-known artists’ colony. Iso saw a great deal of Bunny when he visited Etaples on his honeymoon in 1902; she met him again in the summer of 1907. James Quinn, a fellow Gallery School student, also painted in Etaples at the turn of the century and had a following among the colony of young artists there.
During her early years in Europe Iso continued to exhibit her work in Australasia. She showed Marchand de Volaille in the New Zealand and South Seas Exhibition at Dunedin in 1889-90, a group of landscapes with ‘a poetical tendency and a dignified technique’ with the Victorian Artists’ Society in 1896, and a painting of a peasant girl carrying home a bucket of water in the evening gloom at Mrs Theo Anderson ‘s Studio in Collins Street, Melbourne, in 1908.
Grace Joel described Iso Rae as extremely sensitive and retiring. Nevertheless, she showed her work at the Old Salon in Paris and exhibited in London with the Royal Society of British Artists (1895-1901), the Society of Oil Painters (1898-1907) and other groups. One critic suggested that she carried her impressionist style too far, that the mist through which nearly all her figures were seen was annoying, although another thought it had a ‘rare charm and poetry’ combined with ‘harmonious colour and vigorous effects’.
In France during World War I Iso was employed in the YMCA camp at Etaples while her sister Alison worked in one of the many military hospitals there. At the end of the war Iso moved to the small village of Trepied, near Etaples, where she stayed until 1932, then went to England to live at St Leonards in Sussex. She died on 16 March 1940 at the Brighton Mental Hospital.