Diana Callahan, 50, of Fishers, Indiana, passed away on September 24, 2026. She was born on November 4, 1975, in Timișoara, România, to parents, Viorel Isac and Ligia Isac.

Born and raised in Romania, Diana’s early life and values were shaped by her family, her faith, and the strength of the community around her. She completed law school and earned her JD, an accomplishment of which she was very proud. After reaching that milestone, she came to recognize that the legal profession was not the path she wanted to follow. Instead, she found her truest and most cherished calling in being a wife and mother, a role she embraced wholeheartedly and with deep love.

Diana was known for always looking her best, for her devotion to her family, and for the care she extended to family and friends alike. She cherished time spent with those she loved and valued the quiet beauty of daily life.

She also found special happiness in life’s simple and comforting pleasures, especially coffee. More than just a favorite drink, coffee held deep meaning for Diana, rooted in the love and admiration for it that her family shared while she was growing up in Romania. She appreciated the warmth, the aroma, and the comfort that a small cup of coffee could bring, and her favorite coffees were those she had from Europe. One of her happiest places was The Reserve Roastery in Chicago, where she and her husband could sit high above the city, look out the windows, and quietly enjoy the moment together. Her husband especially cherishes the memory of their daily routines, the quality time they shared, and the simple peace of a warm cup of coffee enjoyed side by side.

While growing up in Romania, her parents started a new church that had to be organized underground during the era of communism when churches were illegal. Together, they helped their community and the surrounding country by creating a charity that dug freshwater wells in Romania so others could share in the blessing of clean drinking water. That mission became part of the mission for what is now known as The Well Coffeehouse in Fishers, which continues that legacy and has since helped install wells throughout Romania and even Africa. This work remained a meaningful source of pride for Diana.

Diana is survived by her beloved husband, Chris Callahan; her son, Jackson “Jack” Callahan; and her mother, Ligia Isac and many other cherished family members and dear friends. She was preceded in death by her father, Viorel Isac. May her memory bring comfort to those who loved her and continue to inspire all who were touched by her life.

Visitation for Diana will be from 5:00pm-8:00pm on Wednesday, October 7th, 2026, at Flanner Buchanan – Oaklawn Memorial Gardens (Conner Suite), 9700 Allisonville Rd., Indianapolis, IN 46250.

A Funeral Service will take place the following day at 10am, Thursday, October 8th, 2026, at Second Presbyterian Church – 7700 N. Meridian St., Indianapolis, IN 46260.

Memorial contributions in her name may be made to Missio International online here or please mail a check to, P.O. Box 124, Zionsville, IN 46077.

Missio International – Facilitating Ministry in Romania:

Their mission: Developing leadership through a Christian lens to serve individuals, churches, and organizations in Romania and beyond; Connecting people, ideas and resources with God's work in Romania, along with transforming the lives of vulnerable children in Romania through Gospel-fueled rescue, healing, teaching and mentoring.