Sienna works primarily on UN accountability issues, including co-leading global advocacy efforts to secure remedies for victims of the UN-introduced Haiti cholera epidemic. Prior to joining IJDH, Sienna worked as a United Nations consultant on transitional justice and gender-based violence issues, as a public law litigation attorney with the law firm of Herbert Smith Freehills, and as a refugee advocate with the Asylum Seeker Resource Centre in Melbourne, Australia. Sienna earned her LLM at the NYU School of Law, where she was a Hauser Global Scholar, and holds undergraduate political science and law degrees from the University of Melbourne, Australia. She speaks English, French, and Kreyol. ​