De Alwis earned her PhD in socio-cultural anthropology from the University of Chicago, where she was a founding member of the Women Against War Coalition and a winner of the Ruth Murray Memorial Prize for Best Essay in Gender Studies.
[citation needed] De Alwis was a senior research fellow at the International Centre for Ethnic Studies in Colombo, Sri Lanka.
[2] She wrote about feminist issues such as militarised sexual violence and the memorialisation of grief.
[3][4] Writing with Kumari Jayawardena, she explored how traditional perspectives in gender can become fixed during times of conflict, commenting "fundamentalism uses women's bodies as a battlefield in its struggle to appropriate institutional power".
[5] In 2014, de Alwis produced an exhibition with photographer Sharni Jayawardena called "Invoking The Goddess: Pattini-Kannaki Devotion in Sri Lanka" at the India International Centre in New Delhi.