Margaret S. O’Neill, an Edgartown matriarch and former longtime county treasurer who was a rare breed of public servant — a staunchly independent fiscal conservative who carried a bright torch for the public’s right to know — died on March 23 at the Henrietta Brewer House in Vineyard Haven. She was 88.

A working mother who raised her eight children in Edgartown, Mrs. O’Neill was a person of wide-ranging interests. She was a life master in bridge, and her name was long synonymous with the weekly duplicate bridge games she hosted at her home on Upper Main street home for many years. She was a women’s business advocate and participated actively in the Zonta Club, a business organization for women that has a chapter on the Vineyard. She was named to Who’s Who in American Women in 1971 for her public service and professional work. And she was always out and about, a petite figure walking the streets of town with her faithful chocolate Labrador retriever Russ at her side.

“I just wonder how I ever found time to work,” she told the Vineyard Gazette in an interview when she retired in 1991.

“This town has been the center of her life and that of her family,” said her son Richard O’Neil in a eulogy following her death.

Margaret Stuhler was born on May 31, 1921 in Edgartown, the first of four daughters of John and Meriam Stuhler. The family first lived in the house on Church street that is today Jeff Norton’s law office. Her father spent summers working as a chauffeur for the Farris family; in the early years the family spent winters in New York city but then moved to Edgartown full-time. Margaret graduated from the Edgartown High School in 1939, winning the Dr. Edward P. Worth scholarship. Following high school she enrolled at the Chandler School of Business in Boston. She had a good head for numbers, which she put to use throughout her career.

As a young woman she worked with her mother and grandmother in the restaurant they owned in the yellow house on Main street. In high school Margaret would leave school to work the lunch shift and then return to school again. She loved to tell the story of how Henry Hough, the editor of the Vineyard Gazette, would arrive for lunch before his wife, Betty, so he could order food that he was forbidden by his wife to eat.

In November of 1940 she married John O’Neil in an evening ceremony at the Sacred Heart Rectory in Oak Bluffs. (Many years later after doing some genealogical research, Margaret changed her last name to O’Neill to match the original spelling.)

They had eight children, first living in the Mary Wimpennny cottage on Morse street and then moving to Upper Main street when the family outgrew the cottage.

When her husband became incapacitated by illness, Margaret went to work, first at the Leroy Vose Insurance company on Main street and then opening her own real estate company. In 1968 she was appointed county treasurer to complete the term of Allan Kenniston. In 1972 she was elected to the post which she held until her retirement in January of 1991.

She felt strongly that the county treasurer should remain an elected position. “I would never have been able to protest bills if I hadn’t been elected,” she told the Gazette in the 1991 interview. “You can’t do the things you would do if your job hinges on what somebody tells you to do. You’re going to think twice before speaking out.”

Mrs. O’Neill was never afraid to speak out — she took on the district attorney, the county sheriff and other public officials over their spending habits, often sparring with them publicly over her unwavering insistence that every penny of taxpayer money be accounted for. After one such dispute with Cape and Islands district attorney Phil Rollins over his expenditures, Mrs. O’Neill wrote in a letter to the Gazette:

“Mr. Rollins paid me the highest compliment when he said I was tight-fisted with the county’s money. Would that there were more of us, and the taxpayers would not have to worry about high taxes.

“Unfortunately, for some spenders of the county money, and fortunately for you taxpayers, my records are open to the public.”

She is survived by four daughters, Margaret Serpa, Sharon Willoughby, Kathryn Bettencourt and Elizabeth Herrmann and her husband Edward of Edgartown; two sons, Stephen O’Neill of Edgartown and Richard O’Neil and his wife Pamela of Naples, Fla.; 12 grandchildren, Ann Rossi and her husband David, J. Anthony Serpa and his wife Lauren, Eric Serpa and his wife Kim, Glenn Serpa, Tricia Willoughby, Gregg Willoughby and his wife Sandra, Karen Hiemer and her husband Daniel, Antone Bettencourt and his wife Erika, Sean Herrmann, David Herrmann, John McMahon and Jason O’Neill; 11 great-grandchildren, Megan, Alex and Matthew Rossi, Joseph and Daniel Serpa, Caitlin and Christopher Serpa, Ava Willoughby, Kassidy, Megan and Annie Bettencourt. She was predeceased by her sons Peter and Michael O’Neill.

A funeral service was held at St. Elizabeth’s Church in Edgartown on March 26. Interment was in the Old Westside Cemetery in Edgartown.

Donations in her memory may be made to Alzheimer’s Services of Cape Cod and the Islands, 72 Main Street, Hyannis, MA 02571, or to the Friends of the Edgartown Public Library, Box 5249, Edgartown, MA 02539.