From PathfinderWiki

New book (Lost Omens Gods and Magic) lists her 5th form being an Anadi, given that the Anadi were never mentioned until the end of 1st/beginning of 2nd edition, either Aranea and the Anadi are the same thing, (only being suggested because of the many features they share) or there is a retcon of this part of Sivanah lore. - Shinx12345