Marie Salvatrix (1874 - 1956) was a Princess and Duchess of Arenberg, a small territory of the Holy Roman Empire in the Eifel region located in western Germany and eastern Belgium. Her father was Engelbert August Anton of Arenberg (1824 – 1875), the 8th Duke of Arenberg and 14th Duke of Aarschot.
I'm always happy to learn a new name that ends in "trix." There's something about that -trix ending that really appeals to me! :) Nicknames for Salvatrix could be Sally or Trixie.