Roulin was first elected as a Councillor for Arsenal ward in 2018 (then called Highbury West ward). Roulin is most proud to secure investment to improve current council homes in the ward as well as deliver new council homes. She is also proud to have introduced people friendly streets in the ward to address long term local traffic, air pollution and road safety issues as well as improving the streetscape for walking, cycling and those with mobility issues. Roulin has been the Executive Member for Equalities, Culture and Inclusion since the May 2022 elections and her portfolio includes leading on equalities and inclusion in the community, migrants, libraries, heritage, and culture.