Tonia Obregah-Xo was the Bene Gesserit nanny to Marie Fenring; daughter of Lady Margot Fenring, and her adopted father, Count Hasimir Fenring. As the Fenring's saw the great turmoil wrought to the Bene Gesserit, after the failure of their breeding program in its' relation to Emperor Paul Atreides, Lady Margot decided to be free of their tutelage and strictures, and chose to raise Marie without their guidance. She did, however, accept a nanny from them; the sister, Tonia Obregah-Xo.