It is with great sadness that the family announces her peaceful passing on December 15, 2017 at her home in Brookline, after a long illness of Alzheimers disease. Beloved wife of the late Michael J. OLeary. Devoted mother to Michael and his wife Jennifer Lynch of Needham, Cornelius Connie and his wife Joanne of Framingham, Kevin of Brookline and Maureen and her husband William Martin of Boston. Loving grandmother to Taryn, Caroline, Devin, Brendan, Marguerite, Michael (Cam) and Erin, and great grandmother to Lukas. Dear sister to Cornelius OCallaghan. In addition she is survived by many nieces, nephews and numerous close friends. She is predeceased by her mother and father, Margaret Casey OCallaghan and Michael Joseph OCallaghan, and siblings, Michael, David, Timothy and Joan. Margaret was born and baptized in Brosna, Co. Kerry, Ireland. She later moved to America in the late 1940s and worked at Filenes and R.H. Stearns & Company. Soon after she met her husband, and raised her family on Naples Road and Ackers Avenue in Brookline. She was a beloved teachers aide and school Crossing guard to generations of school children at The Heath School, and dedicated many years to the Brookline Police. She was active in her Brookline community, made clothing for her children that bore the label Hand made by Margaret OLeary, loved talk radio, and was a faithful visitor to The Mission Church and devoted member of St. Lawrence Church. Visitation will be held on Tuesday December 19th from 4:00 - 8:00 at the Bell-ODea Funeral Home, 376 Washington St., Brookline. Her Mass of Christian Burial will be held on Wednesday December 20th at St. Lawrence Church, 774 Boylston St., Chestnut Hill at 11:00 AM; with Fr. John J. Nichols presiding. Interment will follow at the Walnut Hills Cemetery, 96 Grove St., Chestnut Hill. In lieu of flowers, donations can be made to the Alzheimers Association of Massachusetts, 309 Waverly Oaks Rd., Waltham, MA. www.alz.org or The Basilica of Our Lady of Perpetual Help (The Mission Church), 1545 Tremont St., Boston, MA. 02120.