Waltham - Mrs. Muriel E. (Denault) O'Dowd, of Waltham, died Wednesday, February 13, 2008 in the Emerson Village Nursing Home in Watertown. She was 79 and a lifelong Waltham resident. She was the wife of the late Philip S. O'Dowd; the daughter of the late Joseph and Lydia (Grenier) Denault and the sister of the late Louis Denault. Mrs. O'Dowd is survived by her children, Marcia A. Kneisel and her husband, Fred, of Littleton, North Carolina, Mariellen Lashoones and her husband, Jeff, of Longs, South Carolina, Estelle M. Ferguson and her husband, Paul, of Waltham, Stephen J. O'Dowd of Niceville, Florida and Maureen L. Bonica and her husband, Ted, of Waltham; her sister, Therese Richardson of Waltham; her brother, Joseph Denault, Jr. of East Falmouth; and several grandchildren, great-grandchildren, step grandchildren, step great-grandchildren, and many nieces and nephews. The Funeral will be held on Tuesday at 8 a.m. from The Joyce Funeral Home, 245 Main Street (Rte. 20), Waltham followed by a Funeral Mass in The Blessed Sacrament Chapel of Saint Charles Borromeo Church, 51 Hall Street, Waltham, at 9 a.m. Burial will be in Mount Feake Cemetery, Waltham. Visiting hours will be held on Monday from 4to 7 p.m. Memorials may be made to the American Lung Association, 460 Totten Pond Road, Suite 400, Waltham, MA 02451.