She has completed a law degree at Flinders University, and works as a legal officer for the Shop Distributive and Allied Employees' Association, SA Branch.
Cornes' first political involvement began when she was approached by family friend and State Deputy Premier Kevin Foley to run as the Labor candidate for the South Australian Division of Boothby in the 2007 Federal election, reportedly after her husband declined the nomination.
[4] Despite such negativity, Cornes resolutely conducted her campaign, concentrating on traditional methods such as door-knocking, train stations, street-corner meetings and public forums.
Political journalist Alan Ramsey added some balance to her controversial candidature when he noted:"No candidate for any party in any state emerged with more dignity in "losing" on election night than Cornes.
"[7] After the election, journalist Andrew Bolt apologised to Cornes for calling her a dill on the television show the Insiders, stating:"I still think she was certainly no great candidate, but I very much regret that insult after watching last night's Australian Story.
In 2011, Cornes successfully sued the Network Ten television station for comments made on its AFL-themed panel discussion show, Before the Game, by comedian Mick Molloy.
The joke was in reference to comments Cornes had made in her newspaper column praising Dew for having stated he would be prepared to walk away from his AFL career in order to support his then-girlfriend, actress Teresa Palmer, and describing him therein as "a great catch".