Born Catherine Somerville at Encounter Bay, South Australia in 1856. She was saved from drowning in the Darling River by an Aboriginal girl when two of her sisters were lost. The family moved to Adelaide, South Australia in 1872, and Sophia died, following childbirth, in April of that year. When she was 18, Katie married 35-year-old pastoralist Langloh Parker at St Peter's Church in Glenelg, and in 1879 moved to his property, Bangate Station in New South Wales.Langloh Parker also wrote for the The Bulletin, Lone Hand, Pastoralists' Review and other journals. In 1905 she published an anthropological study of the Narran River Aboriginal people, The Euahlayi Tribe: A study of Aboriginal life in Australia (1905), for which Andrew Lang also wrote an introduction. After her husband died in Sydney in 1903, she met and married Percival Randolph Stow, and she lived with him in Adelaide until her death in 1940, aged 85. She is buried in St Jude's Anglican cemetery, Brighton, SA.