Margaret McDonnell Treadwell

Margaret McDonnell (“Peggy”) Treadwell a family therapist, writer and editor whose work focused on family dynamics and personal development, died on April 14, 2026. She was 84.

Peggy was born on January 22, 1942, in Sheffield, Alabama, the only child of William Francis McDonnell, a lawyer, and Florence Hempstead McDonnell.

She attended Hollins College (now Hollins University) in Virginia, where she studied English and graduated with honors. A year abroad in Paris was a formative experience that shaped her lifelong interest in travel and culture. After graduating from Hollins, she continued to foster her love of travel when she took a job as a flight attendant for Pan American World Airways, where she met her future husband, John P. (“Jay”) Treadwell the company’s director of food service.

After relocating to Washington, D.C., she earned a graduate degree in social work from The Catholic University of America. She began her career working with inner-city youth and disadvantaged families in Washington.

She later established a private practice where she worked with individuals, couples and families. She also worked with clergy from the Episcopal Diocese of Washington. Her approach was grounded in Bowen family systems theory and the work of Edwin H. Friedman, emphasizing multigenerational patterns and emotional processes.

In addition to her clinical work, she was a writer and editor. She served as co-editor of A Failure of Nerve: Leadership in the Age of the Quick Fix, by Edwin H. Friedman, and authored the memoir Please, Just Daisies.

Her husband, Jay Treadwell, died on Feb. 3, 2021. They had been married for 55 years.

She is survived by her two children, Josh Treadwell and Glennon Gordon, and four grandchildren, Lily, John, Nola and Katja.

A celebration of life will be held on May 14th at 11:00 am at St. Columba’s Episcopal Church, 4201 Albemarle Street Northwest - Washington, District of Columbia - 20016