Cornelia “Corny” L. Koster

1930 - 2026

(nee Geary) Entered into the fullness of Eternal Life on February 11, 2026, at the age of 95. Longtime resident of Bayside, formerly of Shorewood. Loving mother of Julie, Patti (Larry) Brant, Mary Murr, John, James and Kitty Koster. Caring grandmother of James (Gabrielle), Ted (Lisa), and Patrick Wagor; Lauren (Mario) Lanza and Genevieve Koster; Mackenzie (Emalee) Koster and Julia (Gurmukh Mangat) Koster; and great-grandmother of Maddie, Ben, Eleanor, Lucille, Joshua, GT, Peter, and Carter. Cherished aunt of Karen Geary, Marguerite (Dan Gershon) Koster, Colleen Koster, Darcy DeGarmo, James and Richard Brooker, Kevin, Michael, and Tim Geary. Dear cousin of Janet Armato. 

She is preceded in death by her beloved husband Henry “Hank” J. Koster, her parents Julie W. and Francis S. Geary; her siblings John (Olive) and Robert (Nina) Geary, and Mary Patricia (Kenneth) Brooker. Further survived by other loving relatives and dear friends.

Cornelia graduated from East High School and Mount Mary University. She had a large circle of friends and was loved by all who knew her, for her kindness, strength, and compassion. She was married to Henry “Hank” Koster for 53 years, until his passing in 2007. They had a wonderful life together full of fun and the craziness of raising six children, which tested both their patience and sense of humor, but they persevered with a lot of love and laughter.  

Corny volunteered with the Christ Child Society of Milwaukee for many years and was a past president and archivist, reflecting her deep love for the welfare of children. 

An avid golfer, she also enjoyed volunteering her time for the GMO and US Bank Championship Golf Tournament. Corny was also a wonderful gardener, and enjoyed time outside tending to the gardens at her Bayside home. 

Her family is so profoundly grateful for the love and care she received during her time at Hamilton House Senior Living in Cedarburg, especially all the staff and caregivers in Legacy Court. Her final days were tended to with compassion and grace by Sharon S. Richardson Hospice in Sheboygan. 

Visitation will take place on Tuesday, February 17, from 10:00AM to 12:00PM, at St. Robert Catholic Church, on the corner of N. Farwell Ave. and E. Capitol Dr., in Shorewood. Mass of Christian Burial will be celebrated at 12:00PM. A reception will immediately follow. Private interment at Holy Cross Cemetery. In lieu of flowers, memorials are suggested to St. Robert Parish or to Sharon S. Richardson Hospice.