Grenith M. Siebert, 82 of Park Forest passed away Wednesday May 12, 2021 at her home surrounded by her loving family. She was born August 7, 1938 in Bessemer, Michigan, daughter of George and Gladys (Mandelin) Mattson. Grenith was employed as a secretary with Governor State University for over 35 years. She enjoyed reading, gardening but most of all she enjoyed spending time with family and friends. Grenith is survived a son, Barry, a daughter Christie (Paul) Schwellenbach, 2 grandchildren, Evan (Amie) Schwellenbach, Jenny Schwellenbach and 1 great granddaughter, Nicole. No services will be held at this time. For guestbook visit www.lain-sullivan.com. 708-747-3700