Kate was born on August 25th 1862 in Horningsham, Wiltshire, England, to parents James Pearce Mansfield and Mary Anne Perryman. Her father was the minister of Horningsham Free Congregational Church, the first Free church in England. In the 1881 census she was described as a Teacher in English and French. At some point she became a governess to a Catholic family and must have been so impressed by their faith that she joined the Catholic Church
Later, Kate decided to devote her life to God and entered a Carmelite Convent in Wells, Somerset where she received the Holy Habit on November 21st 1896 and was given the name of Sister Mary Angela of the Holy Family. On the 23rd of November 1897, aged 35, Sr Mary Angela was examined by the Bishop of Clifton and it was decided she should be received for Profession.