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.
At a party meeting on 17 March 2017, Bryan Green resigned as Tasmanian Labor leader. White was elected leader unopposed, and hence Leader of the Opposition. Almost immediately the Liberal Party went on the attack, releasing a fake CV titled "Student, party hack and MP" referencing White's youth and that she has never worked outside politics. White also expressed the hope that Shane Broad would fill the newly vacated seat, and promised to bring him into the ministry. Because of this the Liberals accused her of bribery, and referred her to the Tasmanian Electoral Commission. White responded that this stance "defies common sense". White announced in December 2017 that under a Labor government she would phase out pokies in pubs and clubs thus breaking the decades long monopoly of Federal Hotels. The reason given was to protect people with mental health issues and the lower socio-economic strata, both of whom are susceptible to pokies addictions. Tasmanians lose over $110 million on pokies every year. This phase out would take until 2023, and would come with a package to help pubs and clubs transition to other forms of revenue. Following the election, White and the Labor party backtracked on their commitment to block the new licences under pressure from the federal party. In February 2018 she declared the ALP would not be supporting the Liberals in attempting to re-introduce the state's anti-protest laws. White promised in the campaign to fund abortion clinics, after the Liberal government cut all funds to them. At the election, White led Labor to a three-seat gain, while paring the Liberals back to a bare majority of one seat.
Personal life
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.