It looks like my guess a week and a half ago turned out to be correct. CD Projekt RED has announced that Ciri will be the second playable character in The Witcher 3: Wild Hunt. It is worth noting that players will not be able to swap between Ciri and Geralt as they wish, but the story will determine when players will step into her shoes.
Robert Malinowski, CD PRojekt RED’s communications specialist describes Ciri as follows:
“She’s a living weapon… and everyone wants to control her. This, plus she also has her own will and agenda, so it’s not just finding her that counts. I think that is the most important aspect of this character. Geralt knows Ciri since she was a child. She’s Geralt’s apprentice and they have a close emotional bond – he trained her so she could become a witcheress.”