After the departure of her two daughters to marriage and children, and then the death of her husband in 1948, Florence continued to live at Glen Foerd. She remained very active in the cultural and social affairs of Philadelphia, until her death in 1972 at the age of 89. At that time, she bequeathed the property to the Lutheran Church in America. She also stipulated that, should the Church no longer be able to sustain the estate, it should pass into the care of the local community. This transition occurred in 1988, and still today, the community organization which is the Glen Foerd Conservation Corporation, and the Fairmount Park Commission, are the custodians of the grounds and the mansion.

From the time Florence became proprietress of the manor, she always shared her parents’ vision of Glen Foerd. Her father, Robert Foerderer, died in 1902 at the age of 43 of Bright’s disease, soon after purchasing the estate and contracting for major renovations to it. He never lived in the house as he had dreamed it would be. Just before his death, he and the architect, Mr. McCawley, had worked out all the plans for building the additional rooms, including the grand staircase. Bedridden with his illness, Robert was visited each evening by Florence and her mother, who would meet at his bedside to report the progress on the house. "Flory, have you played the organ yet? " he asked after the Haskell pipe organ had been installed. Many years later, Mrs. Tonner would often think of his words as she would pass the beautiful instrument and pause to touch the keyboard on which she played so proficiently.

In contributing to the inventory of art initiated by her mother and father, Florence assembled one of the most extensive private collections of prints in the country. She possessed the largest private collection of William Blake’s works in America, which is now housed at the Philadelphia Museum of Art. She also amassed an extremely rare and valuable collection of Bibles. It is believed, that when Carl Sessler, the rare book dealer, went to Germany after World War I, he had a standing order from Mrs. Tonner for all valuable books. It was most likely Sessler who procured for Mrs. Tonner her most prized possession, Martin Luther’s own Latin Bible from which he translated. Also included in this library, was the first Bible ever printed in America, an edition in Native Indian language printed in New England. Another publication was one less than two inches in diameter, a complete King James Bible published in London in 1891 by the Oxford University Press. These volumes can now be found at the Lutheran Theological Seminary.

With gracious generosity, Florence shared her home with others, particularly those who admired the fine arts. She was herself an accomplished poet and painter, as well as a musician. Although she was very secretive and humble about her own achievements, she went to great lengths to encourage young artists, frequently purchasing their work and displaying it.

In possession of a powerful intellect and an adventurous spirit, Mrs. Tonner was an entertaining storyteller, telling tales derived from a vast life experience. She loved to read aloud with her grandchildren, and to spend meaningful time with them. Always the consummate lady, she was gentle, dignified, soft-spoken and friendly.

When her two daughters were little girls, Mrs. Tonner had the little brick house in the formal rose garden, which had been the lead house of the five greenhouses built during Macalester’s tenure, converted into a retreat for them. Florence took special pride in the hybrid tea rose beds, which are still lush with bushes from the finest nurseries in America. Tea hybrids were her favorite flower, and roses were always in her rooms. Shrubbery and flora from countries in the Orient, Europe and South America abounded.

Mrs. Tonner’s connections to her church were deep and sincere. Therefore, she made provisions for Glen Foerd to become a cultural and spiritual center for her church, the Lutheran Church in America, in memory of her parents. The Lutheran Church, in accepting her gift, described Florence in this way, "A chaplet of blossoms adorns her spirit. From early childhood hers has been a life exalted by a vivid sense of noblesse oblige. An aura of gratitude is around her as one spared for deeds of goodness. Her many years have fulfilled the promise of God who commanded: ‘Honor thy father and thy mother.’ She manifests a grecian grace, an openness to all things lovely with a matching symmetry in her own person. Her crown is grace from on high."

Since 1988, when the Glen Foerd property passed into the hands of the Glen Foerd Conservation Corporation and the Fairmount Park Commission, these two organizations have been working faithfully to maintain, restore and preserve the mansion and the grounds that "Flory" had so loved.