Cassidy undertook her PhD in the Department of English, University of Sydney, researching the poetics of Jennifer Rankin and Jennifer Maiden (qq.v.). She has been a member of the Red Room Company, Australia's only poetry company, and has worked for the company as a researcher. Cassidy edited an anthology of new work by writers featured at Sydney's 2005 'The Salon' debate nights, assisted by the Australia Council for the Arts. She has also worked as a casual tutor and librettist.