Scarlet is a U.S.-qualified lawyer and was admitted as a Solicitor in England and Wales in December 2015. She previously worked as an Associate Legal Adviser at the International Criminal Court and as a fellow at the New York Civil Liberties Union, where she investigated the use of solitary confinement in New York prisons. Scarlet received her J.D. from Yale Law School and her B.A. in History and International Studies from Yale University.