Hornell, New York
Margaret A. “Sissy” Mahoney lived a life defined by compassion, creativity, and an unwavering commitment to nurturing others. Whether caring for the sick, inspiring the minds in young students, or crafting works of art, Sissy approached everything with purpose and grace. She died Sunday morning, December 7, 2025, at the Vincent House in Wayland, after a furious battle with cancer.
Born in Hornell on April 22, 1950, to Mark and Eleanor (Gould) O’Neil, The family lived in Hornell until she was 10, then Buffalo, and finally Geneseo, where she graduated from Geneseo Central School in 1968. She pursued her calling to care for others, earning her Associate’s Degree in Science and Nursing from Alfred State College and later her Bachelor’s Degree in Science and Nursing from Alfred University.
From 1971 to 1978, Sissy worked as a registered nurse at Strong Memorial Hospital in Rochester, primarily in the Medical Surgical Department. In 1978, she became an ICU nurse at St. James Mercy Hospital in Hornell. In 1986, she was asked by Father Elmer Schmidt to become a teacher at St. Ann School in Hornell.
For 19 years, Sissy was a beloved third-grade teacher at St. Ann’s. Sissy had an extraordinary gift for recognizing an individual’s talent and fostering the growth of that talent. She was especially great at discovering a student’s “artistic side.”
After retiring from teaching in 2005, Sissy returned to nursing at Hornell Gardens. There, she resumed caring for patients including her Mother, Eleanor, until her retirement in 2010.
She was a devoted member of Our Lady of the Valley Parish and a communicant of St. Ann’s Church, where she served as a Eucharistic Minister and member of the Parish Council. She worked with adult converts through the Rite of Christian Initiation of Adults (RCIA) program, welcoming newcomers to the faith. As a member of the RENEW Program, she helped increase participation in daily and weekly Masses.
With her husband, “Mony,” she worked with Worldwide Marriage Encounter of Rochester. There they helped to further strengthen good marriages.
An accomplished artist, Sissy enjoyed painting & sketching along with general crafting. She especially enjoyed creating “beaded flowers” along with beautiful stained glass wall hangings.
In addition to her parents, Sissy was preceded in death by her son, Thomas John Mahoney; her sister, Brigid Martusewicz; and her brother-in-law, Jimmy Mahoney.
Sissy was married on March 10, 1973, and is survived by her husband Daniel (Mony) Mahoney. Also surviving are her daughter, Sheila (Zachary) Stephenson of Fernandina Beach, FL; two sons, Daniel (Vanessa) Mahoney of Superior, CO and James (Kristine) Mahoney of Charlotte, NC; three sisters, Beth “Honey” (Craig) Ohlhorst of Newport News, VA, Patty (Roger) Dodington of England, and Kathryn “Kitty” (Eric) Hepler of Richmond, VA; three brothers, Mark “Bucky” (Ann) O’Neil of Philadelphia, PA, Timothy (Linda) O’Neil of Canandaigua, NY, and Brian (Julie) O’Neil of Victor, NY; six grandchildren, Kayla Mahoney, Phineas Mahoney, Loretta Stephenson, Sara Mahoney, Delilah Stephenson, and Celia “Oona” Mahoney; along with several nieces and nephews.
Sissy’s family will receive friends on Thursday from 4:00 PM until 6:00 PM at the Dagon Funeral Home, 38 Church St., Hornell, NY. A Celebration of Life will be held at a later date.
Sissy’s family requests that in lieu of flowers, memorial contributions in her name be made to The Vincent House, PO Box 566, 310 Second Ave., Wayland, NY 14572 or by visiting https://vincenthouseny.org/sponsor . Memorial forms will be available at the Dagon Funeral Home.
To leave an online condolence or share a memory, visit www.dagonfuneralhome.com.

I was shocked & saddened to see this. I just saw her in May at Mary’s memorial & I didn’t think that would be the last time. She will be so very missed. She was talented & kind & a joy to be around. Condolences to Mony & her family. May she be in peace with the Lord.
Danny, Marilyn and I send our deepest condolences for your loss.
Sending love to you and your family!
Sincere condolences to the Mahoney family. Fond memories of teaching with Sissy at St. Ann’s. Such a wonderful inspiration for all when she shared her many talents! She will be missed by all who knew her!
My most sincere condolences to Dan and the entire family. What a gifted individual driven to help others as a healthcare professional, teacher, artist. What a life well lived, you have made a difference in so many lives. May you rest in peace, the Angels will guide you to paradise.
Sending condolences to Dan and Family.
Prayers for strength and Peace.
It is heart breaking to think that Sissy is not with Dan, for now anyway, but as much as all will miss her, we know she is home in Heaven and just as determined as ever to love all of us.
Dear Dan and family,
I’m so sorry to hear about Sissy. Obviously I didn’t know her well, but she seemed like such a nice person when we all gathered in Denver for Mom’s birthday those many years ago. I hope you can all remember the good times you had with her.
Lots of love and prayers.
Your cousin,
Marge Carlow