Tétreault was raised in a very religious household. When she was a child, she would hide in the attic where she would read through the stacks of copies of the periodicals published by the Propagation of the Faith and the Holy Childhood Association, both founded to promote the support of the missionary activity of the Catholic Church in Asia and Africa. For her education, her aunt enrolled her in a school in the village run by the Sisters of the Presentation of Mary.