Mary Catherine McMahon, of Lynn, passed away Monday November 10, 2014 in the Life Care Center of the North Shore. She was the daughter of the late Thomas and Mary (Fleming) McMahon. She is survived by her sisters, Eileen Williams of Malden and Josephine McMahon of Lynn, her brother Robert F. McMahon of Lynn and many nieces and nephews. She was the sister of the late James T., Paul and John J. McMahon. Graveside services will be held in Mt. Benedict Cemetery, Boston, on Friday at 11:00 a.m. Relatives and friends invited.