Sister Leanne was born on August 19, 1924, in West Allis, Wisconsin. She was the second of five children, and the first daughter of George and Ann Herda who named her Jeanette Mary. Her baptism took place at Holy Assumption Parish.

Jeanette along with her siblings attended the parish grade school where they were taught by the School Sisters of Notre Dame. She remembered her parents as a sociable and generous couple who gave of their time and talents wherever they were needed.

Impressed by her parents' efforts to help others, Jeanette strove to model their behavior.

Graduating from Holy Assumption grade school, Jeanette attended Pius XI High School, where she met the School Sisters of St. Francis who were her teachers. In addition to her classes, she was active in extracurricular activities which included serving as President of the Catholic Students' Mission Council.

On June 13, 1943, Pentecost Sunday, Jeanette Mary celebrated her Reception in St. Joseph Chapel. She received the name Sister Leanne and felt that the Holy Spirit had been at work by giving her a name that honored two persons she loved: her mother Anna and her brother LeRoy.

In 1949, she completed her Bachelor of Science in Nursing at Alverno College. She continued post graduate studies at Marquette University while working at Sacred Heart Sanitarium. In 1951, Sister Leanne moved to Beaver Dam, Wisconsin. At St. Joseph Hospital, she taught the LPN and RN students. She also worked in the business office as an accountant and business manager. She returned to Milwaukee in 1968 to minister as a registered nurse, working part-time at Mt. Sinai Medical Center and at Sacred Heart Rehabilitation Hospital.

In the mid-1960s and 1970s, the community experienced many changes. Sister Leanne entered into this time of change with great enthusiasm. She became an active member of the Health Agency Council, a province formed especially for sisters working in health care institutions. At this time, sisters were exploring new ways of praying. Along with two other sisters, Sister Leanne started the Center for Reflection in Oak Creek, Wisconsin. She lived there from 1970 to 1973 and welcomed sisters seeking time away from ministry for prayer. These years deepened her own prayer life and called her to take further training in clinical pastoral education while continuing her nursing ministry at St. Anthony Hospital in downtown Milwaukee.

Already in high school, Sister Leanne had dreamed of being a missionary. This dream came to fruition when she moved to Kentucky in 1979 to minister to people living in the hills and hollers of Appalachia. She accepted a position working for the health department as a home health care nurse serving residents of Whitley County, Kentucky.