Complex sentence: Alia never trusted Irulan because of her Corrino heritage and Alia's increasing paranoia; this distrust proved to be well-placed, as Irulan followed Ghanima and Stilgar into the desert during the Fremen rebellion against Alia's tyranny.
Split into simpler sentences: Alia never trusted her because of her Corrino heritage and Alia's increasing paranoia. This distrust proved to be correct, as Irulan followed Ghanima and Stilgar into the desert during the Fremen rebellion against Alia's tyranny.