Sanna is the twin sister of Isadora. Bianca Monroe meets her in the chapter "Sanna" in Antebellum Awakening. Sanna is also a Dragonmaster, though the circumstances of how this came to be has not yet been made clear.
Sanna is nothing like her sister, Isadora. While her twin is calm and quiet, Sanna is loud, boisterous, and obnoxious. She is blind and uses a cane to assist her in walking.