To find out whether or not Alice von Hildebrand was right, I googled "feminism Edith Stein" and got back 3,220 hits. On just the first page of results alone I see these excerpts:
"The life and work of Edith Stein are of immense importance to the women's family planning movement, and to feminism generally"
"Edith Stein became "the voice of Catholic feminism."
"Cross, Nancy M. A Higher Middle Ground: Blessed Edith Steins Feminism.
"To those without faith, Edith Stein's story surely looks like a series ... recognition she deserves for her contributions to feminism, phenomenology, educational"
"Dissertations on Edith Stein as of 7/1/98: TITLE: SIMONE DE BEAUVOIR AND EDITH STEIN: A PHILOSOPHICAL ANALYSIS OF FEMINISM"
You should follow up that "family planning" link - you might be surprised by what you find.