Mary started her career in education as a post primary Science and Maths teacher.

She coordinated the Transition Year programme in St Paul’s Secondary School Oughterard, Galway for a number of years and was appointed Principal of St Pauls in 1994.

In 2005 she was seconded as Assistant National Coordination to the Leadership Development for Schools (LDS) team and coordinated programmes such as Misneach-the programme for newly appointed Principals and Forbairt –a development programme for established Principals and Deputy Principals.

She was appointed Principal of Calasanctius College, Oranmore, Galway in 2010. Mary was elected as President of The National Association of Principals and Deputy Principals(NAPD) in October 2014. She is currently seconded as National Director of The Centre for School Leadership and is completing a PhD in   The University of Galway.

Mary has been a board member of the Center for School Leadership since December 2022.