Gardner was born in
Darwin, and holds a Bachelor of Laws and Bachelor of International Relations from
Griffith University. She worked as a consumer advocate at a community law centre in Australia, and as a solicitor in litigation and banking. She lectured in law at Oxford at
Corpus Christi College, and at the
University of Cambridge, where she is a Fellow of
St John's College. Gardner joined the faculty of the University of Auckland in April 2023, relocating her family of seven from the UK. Gardner has been a visiting fellow at
Princeton University's Woodrow Wilson School of International and Public Policy,
Columbia Law School, the
Max Planck institute for Comparative and International Private Law, and at the
University of Birmingham. She holds a position as an adjunct research fellow at the
National University of Singapore. == Selected works ==