Mary Peterson O’Leary Briggs (“Mimi”)
Mary Peterson O’Leary Briggs (“Mimi”)
July 15, 1939 – January 30, 2026
Mary Elizabeth Peterson O’Leary Briggs, known affectionately as “Mimi,” passed away of natural causes on Jan. 30, 2026, in Boca Raton, FL. Mimi was born in 1939 in Philadelphia, Pennsylvania, to Jesse Dudley Peterson and Edith F. Gorman was raised in Newtown, Connecticut.
Mimi came from a family with deep historical roots. She was a descendant of Richard Warren, a passenger on the Mayflower, and was a lifetime member of the Mayflower Society and the Daughters of the American Revolution. Mimi was the great-granddaughter of Lillia E. Studebaker, daughter of John Mohler Studebaker, of the historic Studebaker family.
Mimi attended the Emma Willard School and later Wheaton College, where she graduated in 1961. Following college, she moved to Boston, where she broke barriers as one of the first women to work as an investment officer at Old Colony Trust Bank, setting the tone for a life defined by intellectual curiosity, independence and achievement.
After marrying Robert A. O’Leary, Mimi settled first in Montclair, New Jersey, and later in Princeton, New Jersey for 33 years, where she raised her three children and became engaged in the civic and social life of all-things Princeton. She was an active member of the Garden Club, the Pretty Brook Tennis Club, and Trinity Church, reflecting her love of community, athletics, and service. In 1980, she ran the New York City Marathon in under 4 hours, a personal achievement she cherished.
In addition to her community engagement, Mimi pursued advanced education, earning a Master’s Degree from The New School for Social Research in New York City. She dedicated her professional career to fundraising and advancement for nonprofit and educational institutions, including Rider University, the Woodrow Wilson Foundation, the United States Equestrian Team, and NJ SEEDS, where her commitment to education, access, and opportunity left a lasting impact.
In 2003, Mimi moved to Marion, Massachusetts, to be closer to her son William and her grandchildren. True to her energetic spirit, she embraced this chapter fully in the next 20 years—playing golf and bridge, and becoming an avid croquet player. She served as Secretary of the Marion Mallet Club and took great joy in the friendships and camaraderie the club provided. At age 74, Mimi met and married Dr. Earland Briggs. Together, Mimi and Earl shared a vibrant life centered around golf, croquet, close friendships, and time at the Beverly Yacht Club. They were snowbirds for the next decade, spending summers at their home overlooking outer Sippican Harbor and winters in Tequesta, Florida, overlooking the golf course.
Mimi was predeceased by her brother, Cornelius “Pete” Peterson X. Mimi is survived by her beloved husband, Dr. Earland Briggs; her children Garrett O’Leary and his wife Lulu O’Leary of London and Dorset, England, and their children Kitty and Robert O’Leary; Liz O’Leary of Washington, DC, and her daughters Katie, Lillie, and Hopie Lovell; and William R. O’Leary III and his wife Alexandra Tolischus of Boca Raton, Florida, and their daughters Tali and Phoebe O’Leary. She is also survived by her great-granddaughter, Grace Elizabeth Kirby.
Mimi will be remembered for her intellect, warmth, competitive spirit, dedication to education and service, and her unwavering love for her family. Her vibrant personality and beaming smile gave those around her a zest for life. Mimi’s life was marked by curiosity, courage, and connection, and she will be deeply missed by all who knew her.
