The life of Sister M. Cornelia St. Cin was distinctly unique and special. She was born November 19, 1898 in New York City, and baptized on the 25th as Lillian Corcoran, having been placed soon after birth in St. Vincent's Orphanage. She had no information on her natural parents, and lived with the parents who adopted her only a few years. These good French people, Mr. & Mrs. Peter St. Cin of Portage Des Sioux, Missouri, were in their late sixties and were responding to the urging of their pastor, Father Rensmen, to adopt an orphan from St. Vincent's. Their married son and daughter had already given them fourteen grandchildren when Lillian arrived at the age of three and a half years, coming from New York in a box car filled with orphans and their nurses.

Lillian's new parents were wealthy and lavished affection on her. Only five years after finding a family, when Lillian was eight, Mrs. St. Cin died. The dying mother requested that the little girl be educated by the Religious of the Sacred Heart. These Sisters had an orphanage and boarding school in St. Louis, and Lillian was entrusted to them. Mr. St. Cin then moved to Grafton, Illinois. Two years later, when Lillian was ten, he also died. Lillian had happy memories of visits to him during vacations, as well as of his monthly visits to her. After Mr. St. Cin's death, Father Rensmen was appointed guardian to Lillian who continued to live with the Sisters until she was seventeen. At that time she thought of becoming a Carmelite, but God directed her to the Benedictine Sisters of Perpetual Adoration through a lay Sister at the Orphanage who had once been a postulant at Clyde. She was welcomed July 16, 1916 by Mother M. John Schrader, and entrusted to the Postulant Director, Sister M. Blandina Cummins.

On February 3, 1917, a few days after the terrible explosion of the acetylene gas plant, she and her companions were admitted to the Novitiate and care of Sr. M. Eustella Neuthard, the Novice Director. She found this God-seeking director a beautiful example of a truly dedicated religious. The year passed swiftly and on February 9, 1918, she received the name of Sister M. Cornelia and took the vows of stability, conversion of morals, poverty, chastity and obedience, and consecrated herself to the perpetual adoration of the Most Blessed Sacrament, concluding with the surrender of herself to love in the formula, “0 most sweet Lord Jesus Christ, in virtue of Thy most holy passion accept me as a victim of Thy holy love.” On February 16, 1924, she was happy to seal this first contract by making perpetual vows.

As a postulant and novice, Sister M. Cornelia helped with some sewing, but worked mainly in the correspondence department answering letters. After profession, she began work in the printery, learning to operate the various presses, folder, stitcher, cutter - in a word, all the printing machines. From November 1938 until 1946, Sister was manager of the printery and took care of the business correspondence and trips.

Sister M. Cornelia was appointed subprioress at Clyde in February 1946, and served under Mother M. Thiadildis Kraus (Edith Marie): 1946-1947; 1951-1953; and under Mother M. DePazzi Fink: 1947-1951, until November 1953 when she was chosen for a three-year term as Prioress in Kansas City, followed by two three year terms as Prioress in Clyde. In 1962, she became Subprioress in Tucson, with Mother M. Irene Prugger as Prioress. Then November 23, 1965, Sister M. Cornelia became Prioress in Tucson until the General Chapter of February 1968. She celebrated her Golden Jubilee in Tucson just before coming to the Chapter in St. Louis.

Following the Chapter Sister M. Cornelia went to San Diego and gave herself to the work of hospitality, serving as Portress. After a few months in Public Relations work at St. Louis in 1971, she returned to Kansas City and served as Moderator of the Eucharistic Guild, which she had helped to organize in July 1956.

Sister had several serious illnesses and surgeries in the 1950’s and 1960's, but always joyfully acquiesced in whatever God saw fit to give her. In February 1978 she celebrated her Diamond Jubilee in Kansas City. That year it was found the cause was Parkinson’s disease which brought her to the St. Louis Health Care Center on July 10, 1979. From 1983 on she needed complete care. She never failed to express appreciation for the loving care bestowed on her, and continued to manifest a beautiful smile despite her suffering, helplessness and inability to even whisper.

Already in November 1981, she chose the readings and psalms she wished used for her memorial liturgies in the Office and Eucharist. She sought to express death as a Paschal Mystery, for this is the way she regarded it. She wished a joyful celebration filled with God's praise. She concluded a brief sketch she had written of her life with the words: "My vocation has become more meaningful to me through the years and I cannot thank God enough for giving me the call and the grace to persevere. Had I another chance to make a choice of life, I would most assuredly become a Benedictine Sister of Perpetual Adoration."

The St. Louis Chronicle on the day of her death, February 19, 1986, says of her: "Sister M. Cornelia had a merry, joyful, childlike spirit, which she perhaps cultivated by her devotion to the Infant Jesus of Prague. She was generous, compassionate, kind and loving, with an understanding heart and faithful love, giving herself unreservedly and making many friends everywhere."

Sister was eighty-seven years of age and professed sixty-eight years when God called her.