 She was educated at Watsonia Primary School, Watsonia High School and La Trobe University, from which she graduated with a Bachelor of Economics.Prior to her election to the Victorian state parliament, Halfpenny was the secretary of the Food and Confectionery Division of the Australian Manufacturing Workers Union from 1999 to 2006, and Industrial Campaigns Officer of the Victorian Trades Hall Council from 2006 to 2010.She lives in the northern suburbs of Melbourne and has two children.