Roisin began her career at Asda where she spent 20 years, latterly as Retail People Director and then Distribution People Director. Roisin joined Greggs in 2010 as Group People Director and later became Retail and Property Director before being appointed as Chief Executive on 17 May 2022.

Roisin is Chair of the Employers Forum for Reducing Re-offending, a voluntary role working with the Ministry for Justice and New Futures Network.