Lisa McMillan Pennock, 73, of Belleville, Illinois, was born on September 4, 1952, in Centralia, Illinois, and passed away peacefully on January 1, 2026, at Barnes-Jewish Hospital in St. Louis, Missouri. Lisa devoted her professional life to the practice of law, serving others with integrity and compassion. Her faith was an important part of her life, and she was a member of Damascus Road Fellowship in Belleville. She also enjoyed fellowship through the 623 Club Bible Study and was a proud member of the Illinois Bar Association.
She was preceded in death by her beloved parents, Ellis “Bud” McMillan and Marilyn (Gorman) McMillan. Lisa leaves behind her loving husband, George “Sandy” Triefenbach; her children, Thomas (Arielle) Swartwout of Lexington, Kentucky, and Hailey Swartwout of Atlanta, Georgia; and her stepchildren, Jeremy (Katy) Triefenbach of Frisco, Texas, Jane Bannester of St. Charles, Missouri, Gregory Triefenbach of Frisco, Texas, and Christopher Triefenbach of St. Charles, Missouri. She is also survived by her siblings, Jami (Gary) Elmore of Walnut Hill, Illinois, Ellis “Bud” McMillan of Centralia, Illinois, and Michael (Kim) McMillan, along with two cherished grandchildren and six step-grandchildren, all of whom brought her great joy.
Visitation will be held from 2:00 to 4:00 p.m. on Friday, January 9, 2026, at Heil-Schuessler Funeral Home in Marissa, Illinois. A funeral service will follow at 4:00 p.m., with Vance Vyers officiating. Burial will take place at Marissa Township Cemetery in Marissa, Illinois.
Heil-Schuessler Funeral Home in Marissa, Illinois, is entrusted with the arrangements.
