O'Brien holds BAs from the Universities of Cambridge and Manchester, and a PhD from Princeton University. She teaches French literature and language. Her research is on medieval French and Occitan poetry, connections between medieval and post-medieval textualities and hypertextuality, the purpose of reading and its practice in interactive communities, and the integration of teaching and research in learning. Her background has also shaped a broader concern with hybridity, migrancy, cosmopolitanism, and tolerance.
She is part of the UBC Early Romance Studies Research Cluster, and is currently working on a book about early Medieval French and Occitan romance entitled Courting Excess.