Roisha was born in Belfast and grew up in South London before studying modern and medieval languages at the University of Cambridge.
Roisha began her civil service career in the Department for Culture, Media and Sport, working on the Government's bid to host the 2012 Olympic Games. She then ran the Mayor of London's office for eight years from 2008, as the city navigated economic downturn, upgraded and developed new transport systems, and hosted the Olympic Games in 2012.
In 2016 Roisha joined the Metropolitan Police as Director of Strategy and Governance, a role which ranged from improving how the Met used data to bringing in Baroness Casey to review the Met’s culture and standards.
Roisha lives in South London with her three children.