Mary Kay “MK” Leifker, 67, of Dubuque, formerly of Chicago, Illinois, passed away Thursday, August 13, 2026. A memorial service will be held at 11:00 a.m. Wednesday, August 19, 2026, at Casey-McNett Funeral Home & Cremation Services, Cuba City, Wisconsin, with Rev. David Flanagan officiating. Visitation will be held from 9-10:45 a.m. Wednesday, August 19 at the funeral home prior to the service. Burial will take place at Nativity BVM Church Cemetery in Menominee, Illinois.

Mary Kay “MK” was born on January 28, 1959, in Cuba City, Wisconsin, the daughter of Bert and Mary (Tranel) Leifker. As a child, she courageously battled rheumatic fever, a challenge she overcame with remarkable determination and resilience – qualities that remained with her throughout her life. She graduated from Cuba City High School with the class of 1977 before attending the University of Wisconsin-Platteville, where she graduated with honors in 1981. She later earned her master’s degree, further reflecting her lifelong commitment to learning and education.

Following graduation, MK moved to the Chicago area, where she devoted her career to education. She began as a physical education teacher before becoming a guidance counselor and an assistant principal, positively impacting the lives of countless students throughout her career. After retiring from Leyden High School in Chicago, she made her home in Evanston, Illinois. Following a diagnosis of Parkinson’s disease, she moved to Mt. Carmel in Dubuque to be closer to her family, where she received compassionate care.

Athletics was a big part of Mary Kay’s life. She was a member of the first Cuba City High School state basketball team in 1977 and went on to have an outstanding basketball career at UW-Platteville. MK was also a member of several Maryville Construction softball teams that competed at state and national tournaments. She went on to share her passion for sports as a high school basketball and softball coach.

MK embraced life with enthusiasm and adventure. She loved traveling, Cubs’ games, spending time with friends, and staying active through softball and a variety of recreational sports. A devoted sports fan, she faithfully cheered on the Chicago Cubs, Chicago Bears, and Green Bay Packers. She will be remembered for her warm and welcoming smile, strong will, intelligence, athletic spirit, and unwavering sense of individuality. Her determination, kindness, and love for those around her left a lasting impression on everyone who knew her.

Mary Kay is survived by her siblings, Merlin (Pat) Leifker, Spring Green, WI, Bob Leifker, Galena, IL, Jeanne (John) Frantzen, Dubuque, IA, and Marlene Derby, Cuba City, WI; a sister-in-law, Carol Leifker, Thornton, CO; and many nieces, nephews, and a special niece, JoAnn (Troy) Clemen.

She was preceded in death by her parents; her stepfather, Orville Mueller; a brother, Jim Leifker; and a sister-in-law, Rita Leifker.

Memorials in Mary Kay’s name may be sent to Casey-McNett Funeral Home at 123 N. Jackson St., Cuba City, WI 53807.

The family wishes to thank Dr. Ries, Dr. Golden, the nurses and staff of Mt. Carmel Bluffs, the staff of Hospice of Dubuque, and her friends, Diane Hanten and Lois Peart for their compassionate care of Mary Kay.