We share news of the death of Sister Mary Louise Deroin, CSC, who died at 12:22 a.m. PDT on October 20, 2024, in Community Memorial Hospital, Ventura, California. Sister Mary Louise entered the Sisters of the Holy Cross from Boise, Idaho, on September 7, 1954. Her initial profession of vows took place on August 15, 1957.

Please join us in prayer for Sister as we renew our faith in the resurrected Jesus and strengthen our hope that all the departed will be raised to eternal life.

Funeral Arrangements: 

Friday, October 25, 2024 

Prayers in the Presence of the Body with memento begin at 9:30 a.m. PDT Friday, October 25, 2024, followed by the Mass of the Resurrection at Saint Catherine by the Sea Chapel, Ventura, California.

In the intensive care waiting room at Saint Alphonsus Regional Medical Center, Boise, Idaho, hangs a plaque honoring Sister Mary Louise Deroin for her 12 years of service dedicated to the hospital. It states in part, “Her presence, strength, and support have been a blessing for countless people in the midst of trauma, uncertainty, and grief. A teacher, spiritual guide and leader, Sister Mary Louise has been helping people find their way since she began her journey with the Sisters of the Holy Cross in 1954.” A woman religious for 67 years, Sister Mary Louise was beloved and known for her gift of providing guidance and comfort to people in need.

By chance, Mary Louise Deroin’s journey of life began in the same building that would become her final ministry assignment. Born at Saint Alphonsus Hospital on July 19, 1933, she was the second of her parents’ five children. She was a daughter of immigrants. Her father, Andre Louis Deroin, emigrated from France in 1926, and her mother, Marie (Bruneel) Deroin, came from Belgium. The Deroin’s were a poor family, but Mary Louise’s father worked hard as a farmer, and her mother knew how to conserve food and supplies. She attended Collister School, Boise, from third through sixth grade, and then St. Teresa’s Academy, Boise, from the seventh grade until she graduated from high school in 1951. After earning her teaching certificate from Boise Junior College, she taught at Roosevelt School, Boise, for the 1953–1954 school year.

Mary Louise could recall first feeling called to the religious life when she was 13 years old. She wanted to dedicate her life to God as soon as she could but understood that she had to be patient, as she was too young to enter a congregation. Eight years later, on September 7, 1954, Mary Louise entered the Sisters of the Holy Cross, Notre Dame, Indiana. Upon reception of the holy habit, she became Sister Andre Marie, in honor of her parents.

As Sister Andre Marie, she taught in elementary schools sponsored by the Sisters of the Holy Cross for 17 years. She taught first through fifth grade students at schools in California, Washington and Utah. In 1962, she earned a bachelor’s degree in education from the University of Portland, Portland, Oregon. From 1975 to 1976, she was the principal of Bishop Glass School, Salt Lake City, Utah. She returned to using her baptismal name in 1976.

After teaching in elementary schools, Sister Mary Louise began three decades of parish ministry. She coordinated religious education in several parishes in Idaho and Utah for 10 years and then became one of the first women to serve as pastoral administrator in the Diocese of Boise, Idaho, in 1984. She served in this role at three parishes between 1984 and 1992—St. Anthony Parish, Wendell, Idaho; St. Catherine Parish, Hagerman, Idaho; and St. Patrick’s Parish, Eden, Idaho. Sister Mary Louise traveled long distances to visit parishioners and train lay volunteers, so she had a citizens band radio installed in her car as a way to communicate in case of emergencies. Many truck drivers fondly knew her by her handle, “Transistor Sister.” Sister Mary Louise remembered this period as one of the most challenging but happiest times in her life. According to her, she was happiest as a pastoral administrator because, “I could answer the needs of the people and I could use the gifts God gave me—listening, compassion and organization.” Her ministry was featured in a Los Angeles Times Sunday cover story in 1990.

Sister Mary Louise continued her parish ministry throughout the 1990s. She served as pastoral associate for St. Aloysius and Holy Family parishes, New Plymouth, Idaho, from 1993 to 1998. She was the director of ministries at St. Vincent de Paul Church, Salt Lake City, Utah, where she organized new ministries, taught programs for adults, and trained liturgical ministers for five years.

In 2003, Sister Mary Louise began her final ministry assignment at St. Alphonsus Regional Medical Center. Her welcoming smile was an asset as a greeter at the hospital’s front entrance for five years. She then was a patient relations specialist in the intensive care unit until 2015. Sister Mary Louise comforted and listened to families enduring a health crisis, provided spiritual support to those who needed it, and helped people find their way in the hospital. On the telephone or in person, it was clear how important and impactful her calming presence was to those in distress. She later said of her ministry at St. Alphonsus, “It was a joy to meet so many people who, at times, really needed a listening ear and a compassionate word.” In recognition of Sister Mary Louise’s gifts and years she devoted to the hospital, she was honored in 2013 with the highest award an associate at St. Alphonsus can receive, the President Commendation for Dedication and Service.

Although Sister Mary Louise officially retired from her position at St. Alphonsus in 2015, she continued to volunteer at the welcome desk twice a week. In 2018, she transitioned to a ministry of prayer and moved to Saint Catherine by the Sea Convent, Ventura, California. She published her autobiography in 2017, titled Eden to Bliss: My Journey in Holy Cross. She died on October 20, 2024, at the age of 91. Throughout Sister Mary Louise’s long life, she faithfully responded to God’s call to service and bore fruit that will last for years to come (John 15:16). She will be dearly missed by her loved ones and local community as she eternally rests in the kingdom of heaven.

We invite you to donate to the Ministry With the Poor Fund in Sister’s name.