Known as Magpie. The deceased was the second of seven children born to English parents. His siblings were: John born 1857; Sarah Ann born 1860; Isaac born 1861; Joseph born 1863; Jonathan 1865; Lancelot born 1868, all born in Ballarat, Victoria. Their father died in a mining explosion in Ballarat in 1867 before the birth of his youngest son, Lancelot, and his wife died in 1902. George's brother, Joseph, was killed in the shaft of the Broomfield Quartz and Alluvial mine in Victoria. As reported in the The Ballarat Star newspaper on Monday 23 March 1891: "His brother, George Mounsey, and Joseph Archer, his mates, were at the windlass on the surface and heard the ground fall and the deceased moaning. Joseph was brought to the surface an hour and a half later only to discover he had died of a broken neck."
George was well-known in mining and athletics in Ballarat, Creswick and Allendale, Victoria. The informant of his death at Goongarrie was John Ritchie, brother-in-law of the deceased. George's eldest child, Ann, died in 1896 aged 2 months. His son, Reginald, died at Gallipoli 9 May 1915. Five months after his death, another daughter was born to his wife. The following notice appeared in the Ballarat Star Newspaper: "On 28th of September, at Alva Park street, Ballarat, the wife of the late George Mounsey, late of Goongarrie, W.A., of a daughter." The deceased had lived in Victoria for 36 years before arriving in Western Australia.