White grew up in Nugent, Tasmania, northeast of Hobart as a sixth generation Tasmanian. She attended Sorell School, Rosny College and the University of Tasmania, where she studied journalism, political science, and international Business management and marketing. She graduated with Bachelor of Arts and Bachelor of Commerce degrees in 2004. She then worked as a political adviser for Labor MP for Denison Duncan Kerr and later Senator Carol Brown, and was Vice President of Tasmanian Young Labor.

For the 2010 Tasmanian state election, White was endorsed as one of the Labor candidates for Lyons. Her campaign focused on "renewal", pointing out that sitting MPs Michael Polley and David Llewellyn had both been in the parliament for over twenty years. Her advertising made use of Polly Waffle wrappers, "Pollywaffle" being a disparaging nickname for Polley. At the election, White narrowly defeated Llewellyn for the second Labor seat (also defeating the third sitting MP, Heather Butler).

White married her partner, Rod Dann in a ceremony in November 2017. She has one daughter, Mia, who was less than a year old when she was elevated to the leadership, and is regularly with White on the campaign trail.

In February 2018 she declared the ALP would not be supporting the Liberals in attempting to re-introduce the state's anti-protest laws.