Sister Kathleen McDonnell, RSM, age 83, entered eternal rest peacefully on Saturday, November 22, 2025, at McAuley Hall Health Care Center in Watchung, New Jersey.

Born in Perth Amboy to John and Kathryn McDonnell, Sister Kathleen began her education at Saint Joseph Elementary School in Carteret and continued at Saint Mary High School. In 1960, she entered the Sisters of Mercy in Watchung from Saint Anthony's Church in Port Reading, taking the name Sister Mary Kilian before returning to her baptismal name in the late 1960s.

She earned a Bachelor of Arts in Elementary Education from Georgian Court College (now University) in Lakewood in 1970, followed by a Master's degree in Elementary Education from Central Connecticut State University in 1976. Her teaching ministry began at Saint Joseph Elementary School in North Plainfield and continued at Saint John Elementary School in Collingswood and Sacred Heart Elementary School in South Plainfield.

From 1972 to 1981, Sister Kathleen served as principal of Saint Mary Elementary School in South Amboy. She then taught at Saint Joseph School in Bound Brook from 1981to 1995, teaching there until 1987, when she became principal. In 1991, she was named principal of Holy Family Academy, formed through the consolidation of Saint Mary and Saint Joseph Schools. In 1994, she received the Outstanding Educator Award from the Diocese of Metuchen in recognition of her excellence in education.

In 1995, Sister Kathleen transitioned to secondary education at Mount Saint Mary Academy in Watchung, where she served in multiple roles, including technology coordinator, bookstore manager, student council advisor, and coordinator of student activities. Throughout her many years in education, Sister Kathleen was deeply committed to her students and colleagues. She found joy in helping young people grow in knowledge and faith, and her gentle guidance left a lasting impression on all who learned from her.

Sister Kathleen spent her final months at McAuley Hall Health Care Center, embraced by the community she loved. She was predeceased by her brothers Gerald McDonnell, Brian McDonnell, and Jack McDonnell. She is survived by her sisters Patricia Gallagher and Maureen Clark, along with many beloved nieces, nephews, and cousins.

May she rest in peace and continue to inspire all those who were touched by her wisdom, wit, and kindness.

Services will take place at the Immaculate Conception Chapel, 1645 US 22 West, Watchung, New Jersey, on Saturday, November 29.

Welcome Home Service: 10:00 am Mass of Christian Burial: 11:00 am

Burial will take place on December 2 at 11:00 am at Holy Redeemer Cemetery, South Plainfield, New Jersey.

Memorial donations may be made to Sisters of Mercy, 1645 US 22 West, Watchung, New Jersey 07069.