He cycles through the characters, just as he cycles through the games. His next update is Sun Breed, I believe, followed by Follow The Leader and then Secret Summer. In this game when it updates, it cycles Nora/Leanne, then Zoe/Coral, and then Irene, and then back to the top. I'm not positive, but in Sun Breed it seems that the updates alternate the majority of the content between the human sisters, followed by the vampire sisters in the next update (not confirmed, it just seems that way). Follow The Leader is new, so a pattern hasn't appeared yet. Given it's a group of three, it's small enough that content may focus on them all, or he may choose to release focused material for each girl in alternating updates. We'll have to wait and see.