While Jessica Atreides/DE was pregnant to Alia, she went through the Water of Life/DE ceremony to become a Reverend Mother/DE. The Fremen/DE did not know she was pregnant, but she could not refuse the "illuminating poison", even if she knew the effects; Alia's consciousness was permanently altered and became the first of the Atreides pre-born, something Jessica's Bene Gesserit superiors had long feared.