Sasha was first clearly mentioned in Breaking Dawn, when Bella flashes back to Carlisle explaining to her the rules of the vampire world. The immortal children were mentioned, and Carlisle tells the story of Sasha and the immortal child she created, Vasilii. Carlisle did not know Sasha's name, but at the end of the book in the vampire index, Sasha and Vasilii are mentioned with the Denali coven, though struck.