Robert George Sharp married Gertrude Coral Bellett in Hobart around 1905 or 1906. They had three children Robert Charles, Mabel Maysie, Tesla Gertrude.;;Robert Charles married Margaret Fairbrass Andrewartha on 24 April 1935. The couple had a daughter Sally born 1 April 1936 . Sally married Michael Morrisby in 1960. The couple had 3 children Angela, Elizabeth and John. Michael died in 2011. ;;Robert Charles Sharp attended The Hutchins School and graduated from the University of Tasmania as an engineer. He worked with the Department of Public works for many years and was Director from 1948 to 1970. Robert Charles died on 25 April 2007.