RN Collection: Mary Lou McDonald. Sinn Fein Vice President, Mary Lou Mc Donald, will be elected as the new leader and President of Sinn Fein, to succeed Gerry Adams, in February 2018. End. 7/6/2009. Dublin European Election. Sinn Fein President Gerry Adams with European candidate Mary Lou McDonald are pictured arriving at Dublin's RDS today (7/6/2009). Photo: Mark Stedman/RollingNews.ie