Margaret Mary McMahon, (Peggy) was born on March 26, 1924 at Pittsburgh, Pennsylvania to Thomas Joseph McMahon and Mary (Boyle). Her father was born in Liverpool, England and her mother in Glasgow, Scotland. Peggy had three older brothers - James Thomas, Kenneth, Edward and a younger sister, Patricia.

When she was a child, the family lived near Latrobe, Pennsylvania and attended the parish of St. Vincent’s Archabbey where she went to parochial school. Because of difficulties arising during the depression, the family moved to Ohio. She graduated from East High School in Youngstown, Ohio in 1937. She also attended 3 years of night school studying business. The family moved to Bentleyville, Pennsylvania in 1943 when her mother became ill with cancer. Her mother died when she was 19 years old.

Peggy worked for six years at a drugstore in Bentleyville and then in a bank until 1956. Her father retired that same year and Peggy felt free to follow her desire to enter religious life. She entered the Carmel in Elysburg, Pennsylvania in September of 1956 but only remained 2 1/2 months because she felt her father still needed her. She worked as a bank teller for 3 1/2 years but the desire for religious life was still persistent. She again applied to the same Carmel and was admitted in August, 1960. This time she remained only 2 weeks because she felt again that her father was in need of her. Her father died suddenly of a heart attack in October of that year.

After this Peggy eventually moved to Tucson, Arizona where her brother Jim was living with his family. It was there that she heard about the Benedictine Sisters of Perpetual Adoration. Peggy was accepted as an aspirant at our Tucson monastery on Dec. 1, 1961. The Tucson prioress at that time, Mother M. Tharsilla, wrote to the postulant director in Clyde, Missouri saying, “Margaret Mary handles things with a simplicity and maturity that is charming; I am sure you will all be pleased with her.”

Margaret Mary entered the postulancy at Clyde on February 15, 1962. She was invested as a novice on September 15, 1962 and professed first vows on September 12, 1964. She was given the profession name of Sr. Mary Denise and her patron was St. Denis.

She moved to St. Louis in April of 1966 when the novitiate was moved there from Clyde. One year later she was moved to Mundelein, Illinois. She was then transferred back to St. Louis in June of 1968 and there she made Final Monastic Profession on September 25, 1969. She would stay in St. Louis until that monastery’s closure in 2001 at which time she moved to the monastery in Clyde.

To help her settle into this new life in the country she would regale the sisters with what she had heard that morning from the ‘hog report’ on the local radio station. Because she was a natural storyteller with a twinkle in her Irish eyes, sisters were known to stay at table long after the closing meal prayer while she finished up a tale. A favorite story of hers was about the time she unexpectedly walked in on a robbery-in-progress at a Baskin Robbins ice cream store in St. Louis. She would drolly say, “I smiled and kindly held the door open for him (the thief) as he ran out.”

One of Sr. Denise’s great gifts to the congregation through the years was to share her artistic talents in a myriad of creative ways, especially through painting, calligraphy, flower arranging and handling monastery decorating. It was more than just painting or arranging flowers, it was about creating beauty. Many birthday cards, Profession invitations, Jubilee programs and Spirit&Life issues had Sr. Denise’s art gracing their covers. She won an Honorable Mention award from the Catholic Press Association for an S&L cover she designed in 1976. In the 1970’s she designed the new silver emblem for the congregation featuring the Benedictine cross with a chalice and two loaves of bread.

Sr. Denise could look at ordinary objects and envision a lovely table decoration or ornaments for a Christmas tree. It was not unusual for her to spy an object in a dusty attic or barn and use it as the perfect touch in some display. Comparisons to Martha Stewart were not uncommon. Sr. Denise was still arranging flowers for the Clyde community up to two days before her death when she finished making her last Advent wreath.

Sr. Denise celebrated her 90th birthday in March of this year and celebrated her Golden Jubilee this past September. Sr. Denise was preceded in death by her three brothers and is survived by her sister Patricia Gumbert. 

Sr. Denise suffered from a heart condition in her last years. In November of 2014 she was noticeably more tired and not feeling well. On December 1, Sr. Dawn Mills went to Sr. Denise’s room at the Clyde monastery to check up on her after Mass. Sr. Denise had passed on to heaven by the time Sr. Dawn found her. While it was a shock to the community, Sr. Denise never wanted any fuss to be made over her so this was a fitting way for her to meet her Lord. Not long after Sr. Denise was found, Sisters gathered around her bedside to say goodbye and pray for her.

Jesus said to his disciples: “Be watchful! Be alert! You do not know when the time will come. (Mk 13:33) ...so the Gospel from the 1st Sunday of Advent proclaimed on  December 1, 2014. This reading would prove prophetic for our gentle Sr. Denise because our Lord came for her the very next day rather unexpectedly.

Sr. Denise celebrated her 90th birthday in March of this year and celebrated her Golden Jubilee this past September. Sr. Denise was preceded in death by her three brothers and is survived by her sister Patricia Gumbert. 

The Mass of Christian Burial was held on December 6, 2014 and she was interred at Mt. Calvary Cemetery at Clyde, MO.

Sr. Denise will be remembered as a kind, gentle, soft spoken sister with a twinkle in her eye and a little Irish chuckle who left a trail of beauty wherever she went. She was also known as a great fan of Starbucks Coffee so family and friends would often give her gift cards to celebrate special occasions. She not only decorated our monasteries, she decorated our hearts with warmth, love and joy.