Edith Stein

Edith Stein, also known as St. Teresa Benedicta of the Cross, OCD , was a German Jewish philosopher who converted to the Roman Catholic Church and became a Discalced Carmelite nun. She is a martyr and saint of the Catholic Church.

She was born into an observant Jewish family, but was an atheist by her teenage years. Moved by the tragedies of World War I, in 1915 she took lessons to become a nursing assistant and worked in a hospital for the prevention of disease outbreaks. After completing her doctoral thesis in 1916 from the University of Gttingen, she obtained an assistantship at the University of Freiburg.

Source: Wikipedia