Born in Melbourne, Janet was the youngest of eight children of Scottish-born George Russell (pastoralist) and Euphemia Carstairs. Having lost her mother in infancy, Janet became a close companion of her father and lived with him at Golf Hill until his death in 1888. She took a keen interest in the estate and, dissatisfied with her brother Philip's management of it, obtained his consent to oversee Golf Hill herself and restored the property to its former prosperity within a few years.

Janet married English-born naval officer John Biddlecombe in July 1900. The pair had no children. Following his retirement from the Commonwealth Naval Forces, John took over management of Golf Hill with his wife. By 1906 they had registered their Hereford stud, buying pedigree cows and bulls descended from females of elite Hereford families in the United Kingdom. When Charles Reynolds sold his Tocal Stud in 1926, Janet instructed her buyer, Mr A.J. Tanner, to purchase the 'pick of the catalogue'.

Janet continued to run the stud successfully after John's death in 1929, despite a manpower shortage during the Second World War forcing her to sell half of her cattle. Tirelessly she organised exhibitions and sales, bringing home a myriad of awards. In 1947 her cattle won every group prize in the Hereford section at the Sydney Royal Show. In 1950 she sold her 'surplus females' - eleven heifers and thirteen cows - at the Royal Melbourne Show, fetching up to £1,000 for each. A further sale in 1953 saw her world-famous cattle bring in proceeds of £125,000, all of which reportedly went to charity.

Indeed, Janet had long maintained a tradition of anonymous philanthropy, begun before her husband's death. Significant amounts of money went to building projects at the Geelong Church of England Grammar School (now standing at 50 Biddlecombe Avenue, Corio), as well as to the Shelford Presbyterian Church; the Australian Red Cross Society (Geelong branch); and the Royal Flying Doctor Service of Australia. On her death at Golf Hill in 1954, Janet bequeathed her £554,585 estate to a number of charitable organisations including the Bethany Babies' Home (Geelong), the Victorian Association of Braille Writers, and the Victorian Society for Crippled Children.

Devoted to the stud until the end, Janet kept photographs of her prize cattle and detailed notes of their pedigrees. In 1953, the year before her death, she produced The History of Golf Hill Herefords, dedicated: 'To the Hereford Breed in Australia' (National Library of Australia).

Sources used to compile this entry: Biddlecombe, Janet, The History of Golf Hill Herefords, Rodney H. Evans Advertising, Sydney, 1953, 44 pp; Langmore, Diane, 'Biddlecombe, Janet (1866-1954)', in Australian Dictionary of Biography Online, Australian National University, 2006, http://www.adb.online.anu.edu.au/biogs/A130211b.htm.