Mary Agnes Sibley

Mary Agnes Sibley, of Thornton, Colorado, passed away at age 90 on June 19, 2025. She was born on October 9, 1934 in Detroit, Michigan, to Mary Agnes Deck and Milton J. Deck, Sr.

She graduated in 1952 from Immaculata High School in Detroit, Michigan, where she was a Student Council Officer, known for short haircuts, hot fudge sundaes and laughing. After graduating, Mary Agnes worked for General Motors in Detroit and in Denver, Colorado, where she moved because she liked to ski, and it is where she met her husband, Ross. They were founding members of Immaculate Heart of Mary Church where they were very active - Mary Agnes sang as a cantor and volunteered her time in several ways.

On July 29, 1961, Mary Agnes married Henry Ross Sibley, who passed away August 23, 2018. She is survived by her sons, Ross (Ann) Sibley, Mark (Lynn) Sibley, and Paul (Lena) Sibley; daughters, Colleen (Bob) Heitzler, Lisa Sibley, and Marilyn (Chris) Wohlford; and fourteen grandchildren, Kahaiaokaponia (Laura) Sibley, Danny Sibley, Billy Sibley, Craig Heitzler, Kawaipunahele Sibley, Abby (Cory) Sutton, Carly (Patrick) Lovato , Delaney Sibley, Wade (Haley) Wohlford, Landon Sibley, Christa Heitzler, Kendall Sibley, Savanah Sibley, and Agnes-Rose Sibley; her first great-grand child, Sofia, daughter to Kahai and Laura Sibley, is due to arrive in early July; sister-in-law, Sara (Glen) Shaffer; nephews, Trey (Rachel) Shaffer and David (Barbara) Shaffer; and niece, Amy (David) Shaffer Curtis. She was preceded in death by her parents, father Milton J. Deck (1902-1985), mother Mary Agnes Deck (1901-1993), and her brother, M.J. Deck (1930-1988).

Mary Agnes was selfless raising her six children; making lunches and dinner before breakfast started, shuttling between soccer, swimming and paper routes, attending as many sporting events she could - all while working over 25 years at Sears. She also enjoyed playing golf, gardening, early morning walks, cross-stitching, time spent with her grandchildren, and in her later years, cards with friends and reading on her back porch.

Friends and family can pay their respects to Mary Agnes on Thursday, July 10, 2025, at Immaculate Heart of Mary Catholic Church, 11385 Grant Drive, Northglenn, Colorado, 80233, where there will be a rosary service from 10:30 to 11:00 a.m., followed by the funeral service from 11:00a.m. to 12:00 p.m., with a reception immediately afterwards, also at the church. Livestreaming of the service will be at https://urldefense.com/v3/__https://youtube.com/live/GeMj1rw5jLQ?feature=share__;!!B209rIdvvA!ZCKri6mLLXXh1RedtBGni7KB3Y6LcvP4poTMkg6RI_RpuE5mWrCP7WxCStdlEScajgrqUt7GMXUKw5qMQ_BDig$. 

Donations can be made to Boys Town, 14100 Crawford Street, Boys Town, NE, 68010 https://www.boystown.org/ways-to-give/support-our-kids or to Humane Colorado (formerly Dumb Friends League), 2080 S. Quebec Street, Denver, CO 80231 Leslie A. Malone Center - Humane Colorado https://humanecolorado.org/locations/leslie-a-malone-center/