As the finale closes, Stella opens a note from Beatrix. Previously, in exchange for her help to invade the castle, Sebastian revealed that Beatrix, while orphaned in Aster Dell as a baby, has two sisters: Isobel and D’Arcy Daniels. Fans were elated at the nod to the original Winx Club series, in which three witches, known as “The Trix,” Icy, Darcy, and Stormy, were the main antagonists and enemies of the Winx fairies.
Source: https://www.distractify.com/p/is-beatrix-dead-fate-the-winx-saga