Karen Lynn Walker passed away peacefully on October 5, 2026. She was daughter to Edmund and Virginia Kostka, born April 30th 1941. Karen was the oldest of three daughters. She lived in Oklahoma City almost her whole life with the exception of a short time in Chicago in the mid-1970s. She was a graduate of NW Classen High School and Oklahoma University, and worked for many years as a hematologist. In 1973, Karen had her son, John Tiefel. 

She also enjoyed being reunited with a daughter, also named Karen, later in life. Karen loved her dogs, working out at the gym, shopping, good movies, and her family.  She was lovingly cared for by the staff of Luminos Hospice the last few months of her life. 

She is preceded in death by her parents, Edmond and Virginia Kostka, and her sister Jana Wilson.  She is survived by her son, John Tiefel, daughter-in-law Bonnie Tiefel, grandchildren, Jonah, Holly and Greta Tiefel, sister Melinda Holcomb, nephew Chris Holcomb, great-nephew Marek Holcomb, brother-in-law Leonard Wilson, daughter Karen Kalb, son-in-law Martin Kalb, granddaughter Haley Kalb, and great-grandson Wyatt Kalb. In lieu of flowers, please consider making a donation to the ASPCA.