Rose Merfeld was born on a farm near Marble Rock, lowa on Aug. 30, 1896. Both parents were from Germany. As the eldest of a family of ten, she helped to raise her younger sisters and brothers and so delayed her entrance into the convent till Dec. 11, 1924 at the age of twenty-eight. She was invested on Aug. 14, 1925, and professed as Sister M. Marcellina on Aug. 21, 1926. Perpetual vows were made on Aug. 22, 1931.

Sister was good-natured, very kind and matronly, hard-working and extremely sacrificial. She was an excellent cook and for many years had charge of the community kitchen and later of the infirmary kitchen. She bore cheerfully the inconvenience and discomfort of cooking over a hot coal range, the fuel for which she herself carried up the back kitchen steps from the coal shed nearby. At that time the cooks rose at 3:30 a.m. and Sister found it a great hardship not to be able to take a drink before Holy Mass or until after services, which usually lasted until about 8:00. 

Sister loved prayer and devoted each day of the week to a particular mystery of the Rosary. Because of her strong physique, she had charge of ringing the largest of the bells and daily brought the sacrifice of leaving chapel before the Elevation of the Mass to ring the bell. She did this also during Advent when the 0 Antiphons were sung at Vespers.

In later years, Sister complained much of being very tired. Surgery at Maryville Hospital for some apparently minor disorder revealed an advanced stage of cancer. Sister suffered intensely the last month of her life. Before dying, Sister promised to help all who had attended her, and all who would ask her help.

She faced death peacefully and courageously and begged to be told when it would be her last night. She died on Dec. 18, 1945 at the age of forty-nine— significantly on the second day of the 0 Antiphons.