Mary M. (Wilson) O'Meara, age 83, died, unexpectedly, Sunday, March 25, 2012, at Lahey Clinic Hospital in Burlington. She was the beloved wife of the late James E. O'Meara. Born in Boston, January 26, 1929, she was the daughter of the late James M. and Jeannie (Turnbull) Wilson. A 40 year resident of Billerica, she worked at the Lahey Clinic Hospital cafeteria as a cashier for 28 years. She is survived by her son and daughter-in-law, William and Janet Adams of Billerica, her sister, Adeline Donohue of Ludlow, and her sister-in-law, Florence Wilson of Saugus. She also leaves her 6 loving grandchildren and many great and great great-grandchildren. She was the mother of the late Edward Adams and sister of the late James Wilson.