Gardner made her professional debut on 8 September 2001 at the Mount Buller women's aerial event. Since her debut, she has competed the Europa, Nor-Am, and World Cup. Her coach is Michel Roth.
She has participated in two Olympic games; the 2006 Turin Olympics and the 2010 Vancouver Winter Games. Gardner finished 23 in Turin. She has currently qualified for the finals at the Vancouver aerial event.
Her nicknames vary from Gards and Beth to Lizard. Gardner was a gymnast before switching to aerials. She completed a bachelor's degree in Applied Science (Human Movement) at the Royal Melbourne Institute of Technology.