Mary was born May 20, 1949, in Davenport, Iowa to William and Mildred (Mahoney) Kelley, and passed away January 18, 2026. During her childhood, the family moved to Albuquerque, New Mexico, where she later graduated from the University of New Mexico after spending two meaningful years in a Franciscan convent.

Mary built a distinguished career as a CPA and later as a private equity investor. Upon retiring, she joyfully returned to her lifelong passion—cooking. She devoted countless hours to sharing that passion with others, volunteering her time to teach the art of cooking with generosity and enthusiasm.

Mary is survived by her husband Timothy M. O'Brien, daughter Christina Kelley, stepmother/grandmother to Katherine Shephard (Brad)/Addison, Meredith, Rowan; Claire Smith (Tyler)/Auggie, Tucker, Griffin and her brothers Bill Kelley, Mike Kelley (Barbara), and Joe Kelley (Dotty). She was preceded in death by her parents.

Mary was a beautiful soul, inside and out. She had a radiant smile, a sharp and memorable sense of humor, and a gentle selflessness that touched everyone around her. She will be deeply missed by all who knew and loved her.

A celebration of her life will be held on February 10, 2026, 1:00pm at St. John's Cathedral 1340 N. Washington St., Denver CO 80203 .

In lieu of flowers, donations may be made to Children's Hospital of Denver or Saint John's Cathedral .