Shelley has studied dance since the age of three. Deciding on a career as a performer at a very young age, she was able to benefit from a unique secondary education at the Victorian College for the Arts. Born in New Zealand to Welsh parents, Mardon has a special interest in Australian dance.
A graduate of the Western Australia Academy for Performing Arts, she was highly inspired by Jonathon Lunn, Douglas Dunn and Don Asker. She participated in all student productions during her tertiary studies, as well as performing professionally with Fieldworks Performance Group. Prior to joining Tasdance in January 1994, Shelley received a grant from the Western Australian Arts Council to choreograph and present original work at Artrage 1993. This grant resulted in a work for four dancers. While working with Tasdance Shelley performed in Faster Than Photos, Footsteps (Angels in Reeboks), Love Me Tender and Seinn O! (Sing the Past).