A member of MU Barnhall, Grainne has played 1st team rugby for the club in the Leinster League and was elected as the first female president of the club for the 2017/18 season.
She is currently the U18 Girls Team Manager.
She has been a member of the Leinster Branch since 2002 and in that time has served as Metropolitan Area Youth Secretary 2002-17, Leinster Youth Committee Rep 2002-17, Chair Leinster Youths Committee 2015 and is a current member of the Leinster Inclusivity Committee.
She also served as Leinster Senior Womens Team Management 2012-17.
Grainne was appointed to the IRFU Committee in November 2023.