Dr O'Brien is a Postdoctoral Research Fellow at the TC Bernie School of Law here at UQ. Her current research project aims to construct a paradigm of the genocidal process through human rights violations to function as a map to prevent further genocides.

Her research areas include Criminal and International criminal law, human rights law, Feminist and Critical legal theory and military law. 

She is a member of the QLD International Humanitarian Law Committee of the Australian Red Cross and the Advisory Board of the International Association of Genocide Scholars.