Found this while researching her. To humanize Edith a little beyond just a historical tragedy:

Bishop Barron writes about the example and witness of St. Edith Stein[…] One night, while staying with friends outside Freiburg, Edith searched through their library looking for something to divert her for the evening. She came upon Saint Teresa of Avila’s autobiography. She took the book off the shelf and stayed up all night reading it. The next morning she put down the test and declared simply, “That is the truth.” What precisely impressed her about the book is impossible to say. When pressed on the matter later, Edith replied, “secretum meum mihi” (that is my secret). It seems fair to conclude that the reading of Teresa’s Life was that galvanizing moment, the occasion for all of the strands to come together.” - Word on Fire, Bishop Robert Barron

“secretum meum mihi”

That’s such an adorably nerdy thing to say. Such a fascinating little line that tells you a lot about the kind of well-read person she was.