Mary Lena, baptized on the day of her birth, December 12, 1910, was the daughter of Charles and Mary Jovita Mattingly Calhoun. She had three brothers and four sisters. Mary Lena began her formal education and first two years of high school at St. Elizabeth School in Curdsville, where she became a star pupil in spelling bees and arithmetic contests. After completing her sophomore year, she transferred to Mount Saint Joseph Academy. Mary Lena began commercial studies in her junior year and following graduation, she worked four years in a dentist’s office in Owensboro. During her work with the public, she realized the need for dedicated service to the poor and underprivileged. She saw the teaching profession as a way to address these needs. She entered the novitiate at Mount Saint Joseph. On March 18, 1934, Mary Lena received the Ursuline habit and the name Sister Charles Borromeo.
As a novice, Sister Charles Borromeo helped with classes in the commercial department of Mount Saint Joseph Academy. Following profession of vows in 1939, she began teaching grades six through eight at St. Anthony School in Jeffersonville, Indiana. Throughout her teaching career, she was assigned to both high schools and upper elementary grades. She taught commercial in the following high schools: in Nebraska: (St. Bernard Academy, Nebraska City); in Kentucky: New Haven -two separate times, Flaherty –two separate times, St. Alphonsus, Hardinsburg –two separate times, New Haven –three separate times, and Knottsville. Sister taught in the following elementary schools in Kentucky: Waverly, Bardwell, Stanley, Hardinsburg, Stanley, Louisville (St. Columba), and Leitchfield (St. Paul). She was a dedicated, efficient, teacher who loved her students. For a short time between these teaching assignments, Sister served in the Maple Mount Post Office.
Sister Charles Borromeo went to St. Catherine High School at New Haven for the school year 1967‑1968, knowing that she was suffering from cancer. Toward the end of November, she was admitted to St. Joseph Infirmary in Louisville for treatment. She suffered intensely, but patiently and prayerfully, until her death on March 12, 1968. Her remains were brought to Mount Saint Joseph. On March 15, Father Bernard Powers, chaplain, and Msgr. Albert Thompson, retired chaplain, concelebrated the funeral Mass. Sister Charles Borromeo’s remains are buried in the convent cemetery.