comes from a notable political family in Athlone, County Westmeath and has been one of the most successful and influential women in Irish public life. She is a former Deputy Leader of Fianna Fáil and held a number of senior Cabinet positions in the Irish government. She was Leader of the Seanad, where she was also for a time party spokesperson on Northern Ireland. She was a member of Westmeath County Council from 1979-87. She is the sister of the late Brian Lenihan (Senior), Dáil Deputy and Minister. Their father PJ Lenihan was a TD from 1965-70. She was educated at UCD and St. Patrick's College, Maynooth (BA, HdipEd). Mary is a former secondary school teacher and has two sons. She is a frequent guest on radio and television current affairs programmes.
In 2011 she was appointed to the Board of Directors of Educate Together. In 2012, 'Just Mary: My Memoir' was published. It won the 2012 Irish Book Award in the 'Listeners' Choice' category. In it she writes of her family background and her early involvement in politics; of the many senior political figures to whom she was close; of her brother and nephew, Brian Lenihan (Junior), both of whom died before their time; and of her successes and disappointments. The book is like the woman herself: open, warm, and shrewd.