Marlene L. Knap, 83, of Naperville, formerly of Illiopolis, passed away March 29, 2021. Graveside service will be 1:30 PM, Thursday, April 1, 2021 at Harristown Cemetery, Harristown, IL. Brintlinger and Earl Funeral Home, Decatur, is assisting the family with arrangements. Memorials may be made to Resurrection Parish in Illiopolis. Marlene was born April 1, 1937 in St. Louis, MO, the daughter of Roy and Lorraine (Cummings) Pfeiffer. She married Theodore Knap on March 21, 1970 in Pittsfield, IL. Marlene was a payroll clerk for Brown’s Shoes. She enjoyed bowling and loved to travel. She was an active member in the Macon County Home Extension and was a member of Resurrection Parish in Illiopolis. She is survived by her husband of 51 years, Theodore; son, Russ and wife April of Oswego; grandchildren, Liam and Talia; sister, Rosemary and husband Gilbert Knap; brother, David and wife Laurel Pfeiffer; and nieces and nephews, Duane, Leroy, Fred( Michelle), Sandra, Christine, Amy, Michael, Matthew and Andy. Marlene was preceded in death by her parents and her brother, Paul Pfeiffer.