Wow, I never thought of it that way...This is so accurate. Charlotte keeps hiding her emotions from everybody, and then she, later on in the story, becomes one of the those characters who can't handle their guilt and sadness and burden anymore and just lets it all out in an emotional, dramatic speech battle.
As for Saphira, I personally think she's hiding a secret. She seems to be so strong and mighty outside, but something tells me her inside is not as strong.
I think Laura might have the most positive development overall. Seeing as she is currently potrayed as weak, she might gain