Sheila Mae Miller, age 76 years, 9 months, and 21 days, passed away peacefully on Saturday, July 5, 2025, at Mayo Hospital in Phoenix, Arizona, following complications from Legionella (Legionnaires' Disease), which she contracted while recovering from treatment for Multiple Myeloma.

Sheila M. McGillivray, born on September 14, 1948, in Iroquois, South Dakota, to Charlie and Margaret McGillivray, spent her early years in Huron, SD. During her junior high years, her family relocated to Sioux Falls. A proud graduate of Washington High School, Class of 1967, Sheila met her lifelong partner, Mike Miller, during her school days. Their first date was on July 17, 1965, and they shared a lifetime of love and devotion, recently celebrating their 56th wedding anniversary on May 17, 2025. Together, they raised two children, a son named Brent and a daughter named Kelly.

After graduating from Stewart's School of Hairstyling, Sheila moved to Minneapolis, MN to begin her career. Following her marriage to Mike, she furthered her education at Nettleton College, where she transitioned into office and accounting work. She eventually retired from the Minnehaha County Auditor's Office (DMV) in 2009. In 2010, she and Mike enjoyed a summer home in their beloved vacation destination in Crosslake, Minnesota. This enabled them to be sunbirds in Arizona. In 2023, they relocated to Phoenix to be closer to their daughter, Kelly, and to have access to healthcare at the Mayo Clinic during Sheila's cancer treatment for Multiple Myeloma.

Sheila, a determined and courageous woman, triumphed over her cancer diagnosis and overcame Type 2 diabetes in December 2024. However, just days after attending a Cardio Dance class at her community center, she fell ill while still recovering from CAR-T cell therapy. Within a few days, her condition rapidly deteriorated due to pneumonia caused by Legionnaires' Disease. Despite her strength and unwavering will to live, she passed away on July 5th at 12:38 p.m., surrounded by loved ones, and entered eternal rest.

Sheila will be fondly remembered for her infectious and loving laugh, a trait her family attributed to her Irish heritage. She loved playing Bunco! She played with her Bunco girls for over 30 years in Sioux Falls and several years in Arizona.  Over the years, she found joy in playing bingo, quilting, and cherishing time with her loved ones and all her four-legged friends. Her joyful presence and vibrant spirit had a way of brightening every room she entered.

She is survived by her husband of 56 years, Michael R. Miller; son Brent (Cathy) Miller of Sioux City, Iowa; daughter Kelly (Caleb) of Ahwatukee, Arizona; sister Patricia "Pat" Miedema, Waite Park, Minnesota; and many cousins, nieces, nephews and dear friends who will miss her deeply.

Sheila was preceded in death by her mother, Margaret Christensen; father, Charles McGillivary; brothers William (Bill) of Junius, South Dakota, Donnell (Don) of Pierz, Minnesota, Neal of Canton, South Dakota; and Duane, California.

A celebration of Sheila's life will be held in Sioux Falls, at a later date. This gathering will allow her loved ones, both near and far, to come together and remember her beautiful life.