ibeforem
I think the main thing Scarlet has going against it is that there are two focuses to the story. First, you have the further adventures of Cinder and Kai, moving the overarching plot forward. Second, you have the new story, centered around Scarlet and Wolf (as in Little Red Riding Hood).
Scarlet is a farmer who lives with her grandmother in the French countryside. But unfortunately, her grandmother has gone missing and no one seems to want to do anything about it. So Scarlet takes matters into her own hands, helped by the mysterious Wolf.
Of course, Scarlet’s story ends up intertwining with Cinder’s. We learn some things that I had already guessed, but it was nice to have them confirmed. I think my main issue was that I just didn’t get enough time to know Scarlet before I was thrown into the action and expected to root for her.