RITTER, Ruth Katherine (nee Willet), beloved wife of the late   Robert A. Ritter, devoted mother of Joseph and Jean Collini,   Robert and Colleen Ritter and Jacqueline Collini Darpel.  Loving  grandmother of ten grandchildren and nine great-grandchildren.  Loving daughter of the late Joseph and Mildred Willet and dear  sister of the late Joann Engle.  On Sunday, May 21, 1995, at   69 yrs.  Visitation B.J. Meyer Sons (Colonial) Funeral Home  3726 Warsaw Ave., Wednesday, 6 to 9 P.M.  Services will be held  Thursday at Spring Grove Cemetery Norman Chapel at 10:00 A.M..  Member of F.O.P. Auxiliary.