Joan was born in Detroit, Michigan, to the late Robert and Helen Houghten. She grew up on Detroit’s east side alongside her three sisters: Gail (Herbert), Patricia (Nick), and Pamela Natzke, who preceded her in death.
Joan shared a remarkable life and love with her beloved husband, Charles H. Thornton III, to whom she was married for 73 years. Together, they built a family rooted in faith, adventure, and deep devotion to one another.
A lifelong champion of women’s fitness and healthy aging, Joan lived her values every day. She ran three marathons, including one on the Island of Hawaii, and co-founded Vital Options Fitness, which she grew into a successful business franchised throughout the state of Michigan. Later in life, she continued her passion for helping others as a balance and mobility instructor at SOC.
Joan’s commitment to learning and service was extraordinary. She held degrees in Health Services, Gerontology, and Exercise Science, with a minor in Religious Studies. She served her community as a council member for the Detroit Area Agency on Aging, the Grosse Pointe Woods Senior Citizens Commission, and as a Wellness Coordinator for Services for Older Citizens, advocating tirelessly for the well-being of older adults.
Family was the heart of Joan’s life. She treasured every opportunity to be with her children and grandchildren. Joan and Charles were avid boaters who loved spending summers on the water, especially at Club Island, creating memories that will be cherished for generations.
Joan was a devoted Christian Scientist and a longtime member of the First Church of Christ, Scientist, in Grosse Pointe Farms, where her faith and kindness touched many lives.
She is survived by her loving husband, Charles H. Thornton III; her children Kyle Thornton, Shari Alber (Phillip), Charles “Chip” Thornton IV (Mary), and Krista DiLuigi (Jim); and her cherished grandchildren Emily Alber, Phillip Alber (Kathleen), Elisabeth Mulligan (John), Christian Alber, Erin Thornton, Charles “Chase” Thornton, Allie DiLuigi, Lilly DiLuigi, and Jack DiLuigi.
A funeral service will be held on Wednesday, January 7, 2026, at Kaul Funeral Home, 2843 E. Jefferson Ave., St. Clair Shores, Michigan 48081. Family visitation will take place from 2:00–3:00 p.m., followed by public visitation from 3:00–8:00 p.m. A small, non-denominational service will be held at 6:00 p.m.
In lieu of flowers, memorial donations may be made to the Grosse Pointe Animal Adoption Society (GPAAS).
