Mary Kostic Obituary

Mary Kathryn Kostic passed away on February 17, 2025, at the age of 88 in Thornton. Born on July 18, 1936, Mary Kay, as she was affectionately known, leaves behind a legacy marked by dedication to her family, career, and community.
Mary Kay graduated from Saint Mary's High School and furthered her education at Regis University. Her career was notably spent at the Department of Finance and Accounting Service (DFAS), where she retired as an oracle programmer. Her professional life was complemented by a vibrant personal life filled with activities that spoke to her passions.
A devout member of the Immaculate Heart of Mary Catholic Parish, Mary Kay's faith was a cornerstone of her existence. She was deeply involved in her community and cherished the friendships she made through her church.
Her hobbies included gardening, where she took particular pride in her tulips and roses, and playing softball, where she was a spirited member of her work team. Mary Kay was also an enthusiastic genealogist, tracing her family roots back to Ireland, an endeavor that led her to become a recognized Daughter of the American Revolution.
Mary Kay was preceded in death by her beloved husband, Bill Kostic, in 2020; her brother, Gene Turner; sisters, Donna Reising and Janice Lemek; and nephews, Tom and Doug Reising. She is survived by her youngest sister, Elizabeth Crow, and her son, Bill.
Contributions in memory of Mary Kay can be made to the Immaculate Heart of Mary Parish in Northglenn, Colorado, or to EWTN, reflecting her commitment to her faith and community. Her life was a testament to her strong will, loving heart, and unwavering faith, and she will be deeply missed by all who knew her.