Roberts modelled this portrait of his and Lillie’s only son, Caleb Roberts (1898–1965), on the eve of his ninth birthday. Ca, as his parents affectionately called him, was born in Balmain in Sydney’s inner west and named after Lillie’s father. Educated in England after the family moved there in 1903, Caleb was awarded the Military Cross during the First World War. He returned to Australia to work as an engineer at the Victorian Country Roads Board in 1923.