Snow, Marion H. (Peterson) of Lexington . Dec. 15, 2011. Loving mother of Cheryl J. Ricci of Waltham and Deborah S. Nelson of Bedford. Dear grandmother of Peter L. Ricci of Waltham, Amanda L. Ricci of Plymouth, Andrew G. Nelson and his wife Brenda of Northborough and Jeffrey D. Nelson of Mountain View CA. Great-grandmother of Mara, and Miles. Sister of Norman H. Peterson and his wife Maria of Lexington. Also survived by 2 nephews and 1 niece. Funeral services will be held at First Evangelical Lutheran Church, 6 Eddy St. Waltham, on Tues. Dec. 20 at 11 am. Relatives and friends are kindly invited to attend. Visiting hours at the Douglass Funeral Home, 51 Worthen Rd., Lexington on Monday Dec. 19 from 5-8 pm. Memorial donations in her memory may be made to the American Cancer Society, 30 Speen St., Framingham MA 01701. Interment Westview Cemetery Lexington.