Peter Leslie Plummer was born in 1901 in Queanbeyan, New South Wales. He is the son of Peter Plummer and Clara Gabriel. Peter married Mary Mackay on 6 April 1923 in Wollongong, New South Wales. Mary was born in 1905 in Cambewarra, New South Wales, and is the daughter of Samuel Mackay and Elizabeth "Eliza" Hockey. Mary died on 28 July 1929 in Wollongong, New South Wales. Peter married Phyllis Elizabeth Jane Green in 1943 in Wollongong, New South Wales. Phyllis was born in 1908 in Wollongong, New South Wales. Phyllis died on 28 October 1995 in Dapto, New South Wales. Peter died on 2 February 1979 in Wollongong, New South Wales.

William Peter (Billy) Plummer was born in 1923 in Wollongong, New South Wales. He is the son of Peter Plummer and Mary Mackay. Billy died on 3 April 1965 in Sydney, New South Wales.

Constance Joyce (Connie) Plummer was born on 9 April 1924 in Wollongong, New South Wales. She is the daughter of Peter Plummer and Mary Mackay. Connie married John Wonson McAndrew on 12 December 1942 in Church of England, Wollongong, New South Wales. John was born on 26 December 1921 in Wollongong, New South Wales, and is the son of L. McAndrew. John died on 3 March 1972 in South Australia. Connie died on 18 August 2013 in Thirroul, New South Wales.

Daphne Frances Plummer was born on 23 August 1925 in Wollongong, New South Wales. She is the daughter of Peter Plummer and Mary Mackay. Daphne married Raymond Arthur Armstrong on 3 April 1944 in Wollongong, New South Wales. Raymond was born on 30 March 1905 in Bowral, Wingecarribee Shire, New South Wales, and is the son of Ernest Arthur Armstrong and Elizabeth Ann Halls. Raymond died on 22 June 1990 in Bowral, Wingecarribee Shire, New South Wales. Daphne died on 7 April 2010 in Bowral, Wingecarribee Shire, New South Wales. They are buried in Bowral Cemetery, Bowral, Wingecarribee Shire, New South Wales.

Raymond Kenneth Plummer was born in 1927 in Wollongong, New South Wales. He is the son of Peter Plummer and Mary Mackay. Raymond died on 10 October 1951 in Wollongong, New South Wales.

Robert (Bobby) Plummer was born on 21 July 1929 in Wollongong, New South Wales. He is the son of Peter Plummer and Mary Mackay. Bobby died on 28 May 1996 in Wollongong, New South Wales. He is buried at Unanderra, Wollongong, New South Wales.