Sheila A. Dennis, 77, of Stockton Drive, Middletown, RI, died peacefully at home on Monday, December 26, 2016 with her family by her side.She was the wife of 58 years to John F. "Frank" Dennis.Born in Newport, RI on January 5, 1939, she was the daughter of the late Martin Sullivan and the late Margaret F. Mattila, and the step-daughter of the late Martii Mattila.Sheila was a secretary with the Newport School Department for many years before retiring. She enjoyed gardening, bird watching and traveling. She especially enjoyed spending time with her family.In addition to her husband, she is survived by her daughters, Debbie Dennis Anthony and her husband, Jack, of Middletown, RI, Claudia Dennis and her husband, Andy Gillespie, of New Smyrna Beach, FL, and Lisa Guillemette and her husband, Jerry, of Tiverton, RI; her brothers and sisters, Martin Sullivan of Portsmouth, RI, Maureen Brady of Eden Prairie, MN, Martii Mattila of Pompano Beach, FL, and Patricia Turner of Fayetteville, NC; her four grandchildren, Covell Anthony, A.J. Dennis, Charlotte Guillemette and Joshua Guillemette; and many nieces and nephews. She was the sister of the late Peter Mattila.Services will be private.In lieu of flowers, donations in her memory may be made to the American Cancer Society, 931 Jefferson Blvd., Suite 3004, Warwick, RI 02886 or to VNS Hospice of Newport Bristol Counties, 1184 East Main Road, Portsmouth, RI 02871.