Cassie Jansen
O Fallon | Save
Cassie René Jansen (nee Brenner), 53, of O’Fallon, IL born on March 28, 1972, in Belleville, IL, passed away on Monday, February 23, 2026, peacefully in sleep at home.
Cassie had always dreamed of becoming a mother, and when her children were born, she truly came into her own. She radiated love, joy, and laughter, and her children were without question her greatest pride and deepest joy. Family meant everything to Cassie. She treasured time spent together—whether gathered around the table for family game nights, camping under the stars, or sharing stories and laughter around a bonfire.
She found a sense of freedom and peace in the wind, embracing “wind therapy” on the back of a Harley whenever she had the chance. Her love for children extended beyond her own family into her career. For the past 15 years, she devoted herself to teaching in O’Fallon District 90, where she touched countless young lives with her warmth and dedication.
When she wasn’t busy being a loving mom, devoted teacher, sister, or daughter—or enjoying a ride on the open road—Cassie could be found laughing with friends, a Bud Light in her coozie, playing pool, talking a little friendly smack, and often running the table. She felt most at home near the water—whether it was a pool, lake, or ocean. The warmth of sunny days and the fun they brought perfectly matched her vibrant spirit.
Cassie was preceded in death by her parents, Paul Carl and Linda Jo Brenner (nee Skinner); maternal grandmother, Jackie Skinner; paternal grandmother, Marie “Mema” Brenner; former mother-in-law, Shirley Jansen.
Left to cherish Cassie’s memory are her significant other, William Starns of Lebanon, IL; two children, Paige (Eric Manzano) Moore of O’Fallon, IL, Gavin (Revanth Onteddu) Jansen of O’Fallon, IL; three step-daughters, Jasmin Starns, Lily Starns, Lilah Starns all of Lebanon, IL; one sister, Katie Brenner of O’Fallon, IL; two grandchildren, Declan Moore, Joedis Manzano; and one niece and nephew, Sammy Riley, and M.J. Riley.
Memorials may be made to O’Fallon Consolidated School District #90. Condolences may be extended to the family online at www.schildknechtfh.com.
Visitation will be held on Friday, March 6, 2026, from 4:00 p.m. – 7:00 p.m., at Schildknecht Funeral Home; 301 S. Lincoln Ave., O’Fallon, IL 62269.
Funeral services will be held on Saturday, March 7, 2026, at 11:00 a.m., at Schildknecht Funeral Home; 301 S. Lincoln Ave., O’Fallon, IL 62269. Burial will follow at O’Fallon City Cemetery.
Arrangements have been entrusted to Schildknecht Funeral Home.
Schildknecht Funeral Home
