Esther C. Bonnet, a longtime advocate of causes of the elderly who was a founding member of Action in Maturity and worked to improve the Barclay Elementary School library, died in her sleep Monday at Symphony Manor assisted living in Roland Park.

She was 104.

“Esther Bonnet was a quiet lady who led revolution after revolution in our neighborhoods, and they were all for the good,” said City Councilwoman Mary Pat Clark, who got to know Mrs. Bonnet when both were members of the Greater Homewood Corp., now Strong City Baltimore. “She was not loud, but her actions were loud. She was one of a kind, and we’re really going to miss her and we’re going to keep her legacy going.”

“My kids went to Barclay School, and that’s where I got to know her, one volunteer to another, and we were also members of the Greater Homewood Corp. We both had a passion for that school,” said Jo Ann Robinson, who lives in the Abell community and is a former president of the neighborhood association.

“She had a very sweet way of insisting you do what she thought you should do, and before you knew it, you were doing it,” she said.

“She was just remarkable, and she touched all of our lives. She had great compassion for good causes,” said Marilyn P. Tabb of Guilford, a former teacher and a Barclay Elementary School volunteer.

The daughter of the Rev. Gustavus Bechtold, a Lutheran minister, and Leona Wetmore Bechtold, Esther Caroline Bechtold was born in Ocean Grove, N.J., and raised in North Philadelphia, where she graduated in 1929 from Olney High School.

She was a 1934 graduate of Tennent College, which is now part of the Princeton Theological Seminary in New Jersey, with a degree in religious education.

In 1936, while working in the administrative office of Lankenau Hospital, then located in North Philadelphia, she met a recent medical school graduate, Dr. Philip Dirlam Bonnet, when he arrived for a job interview.

The couple married in 1940.

After moving to Boston in 1948, Mrs. Bonnet began working in social services as a volunteer and later as a paid professional.

Inspired by her father’s work with the poor, she worked in a settlement house and at the YWCA. She also volunteered with several Boston hospital auxiliaries.

In 1966, the couple and their family left Boston for London, where Dr. Bonnet was a consultant to a British medical group.

In 1967, when Dr. Bonnet joined the faculty of what is now the Johns Hopkins University Bloomberg School of Public Health, they settled into a home on Beech Avenue in North Baltimore.

Dr. Bonnet, who later was president of the American Hospital Association, died in 1999.

With her five children in school, Mrs. Bonnet worked at Hutzler’s department store and at the Maryland Casualty Co.

Mrs. Bonnet’s activism was inspired by the purchase of various apartment houses in the Homewood neighborhood by the Johns Hopkins University, which displaced elderly residents.

As a member and later board member of the Greater Homewood Corp., Mrs. Bonnet saw the need for services for seniors and was a founder of Action in Maturity, or AIM, in the early 1970s.

“We started that together and the bus service which took the elderly to hospitals and shopping from high-rises all over the city,” said Ms. Clark.

“Esther invented that bus service against all the odds. She just wanted things better for the elderly before she was aged,” she said. “And it’s still going today. You see those buses all over the city.”

Mrs. Bonnet also worked with the Govans Ecumenical Council, Family and Children Services of Central Maryland-Elder Services, served as chair of Stadium Place senior housing on the site of the old Memorial Stadium, and served as a member of the Baltimore Commission on Aging.

Improving the library and tutoring students at Barclay Elementary School became another cause for Mrs. Bonnet, who joined the effort in 1968 at the school that was led by the Woman’s Club of the Johns Hopkins University.

Jenny L. Heinbaugh spent 30 years at Barclay Elementary, beginning as a teacher and eventually rising to assistant principal, and finally serving as principal from 2008 to 2013, when she retired.

“At Barclay, she was dedicated to providing services we didn’t have. She wanted a library for our children, and she loved reading to the kids,” Ms. Heinbaugh said.

Mrs. Bonnet and other Woman’s Club members took on the task of reorganizing and updating the library after the Maryland State Department of Education revoked its standing as an accredited library. The standing was later restored, thanks to the efforts of the volunteers.

She recruited additional volunteers, was present at all work sessions, and even took home damaged books that her husband was able to restore in his workshop.

“Esther was a true gem — coming to school each week and teaching my students the love of literature,” Ms. Heinbaugh, who lives in Germantown, Montgomery County, wrote in an email.

When Ms. Heinbaugh became principal and the school’s budget did not allow for a media specialist, Mrs. Bonnet stepped up to help operate the library.

“Esther embodied our commitment to being a community school. In addition to volunteering in the library, she served on our School Improvement Teams and also supported our school through First English Lutheran Church — another community partner who provided much-needed assistance,” Ms. Heinbaugh wrote.

“In recent years, she walked with two canes, but that did not stop her from coming to Barclay. And sometimes the elevator wasn’t working, but she was determined to make it to the third-floor library,” she wrote.

Mrs. Bonnet’s visits to the school became less frequent as she grew older, and they finally stopped in 2014.

“But we knew she was there in spirit,” Ms. Tabb said. “There is a hole in our hearts because of her death.”

A resident of Symphony Manor since 2012, Mrs. Bonnet did not follow a particular regimen to reach centenarian status.

“She never smoked and did not avoid certain foods. She liked an occasional glass of wine or a drink. She took everything in moderation,” said a daughter, Deborah Tupper of Stoneleigh.

Mrs. Bonnet enjoyed playing bridge and gardening. She kept fit, her daughter said, for many years by hiking and taking nature walks.

She also played the piano and was a fan of opera.

A memorial service for Mrs. Bonnet will be held at 11 a.m. July 8 at First English Lutheran Church, Charles and 39th streets, Guilford.

In addition to her daughter, she is survived by two sons, Philip Bonnet of Geneva, Switzerland, and Christopher Bonnet of Sarasota, Fla.; two other daughters, Caroline “Bonnie” Akins of Dover, Mass., and Priscilla “Bitsy” Ellis of Lake Oswego, Ore.; a sister, Leona Souser of Kennett Square, Pa.; 11 grandchildren; and 14 great-grandchildren.

frasmussen@baltsun.com