Bella

Confidence.

That's what she is. She's a stand on her own feet kind of girl. She just needs to remember that. Rosalie does, too. Rosalie, at first, treated her as a thing, as a problem, and Bella felt that, and her confidence went away in Rosalie's presence. Now Rosalie is (unconsciously) saying "I need you." Even if that need is to answer a phone call from Isle Esme and to become Bella's champion. Even if that need is to watch the baby while Edward and Bella have a little sweetie time. And that need of Rosalie's is the light of the sun, opening the flower of Bella's confidence again.

That's Bella, too: she very much depends on what others think of her. The first day at Forks high, when everybody was like: "Who's this out-of-town girl?" She shrank down to a nothing wallflower. It was only when she established in her mind her place in her new vampire family that she began to be herself again. Pre-visit to the Cullen mansion, Bella was a scared little mouse of a girl, not knowing what shirt to wear. But when Esme looked at Bella, and said: "You are brave; I love you; You are my daughter." and Alice handed Bella her BFF creds, then nothing in the world could shake her: not high school, not James, not overbearing Edward driving her away from the baseball field to nowhere. Nothing. She had love, support and a place in her new family, and her feet were firmly planted on that solid foundation.

Sure, Bella shouldn't depend on others for her confidence ... if she weren't Bella. But she is, and intrinsic to her is the comfort of others. Bella is not just Bella or only Bella, she is part of a family, the central part, the part that makes sure everybody is okay and shining and in front being the hero. That is her happiness: if you are happy, she's happy. If not, she won't be happy until she finds a way to restore your happiness.

AND she's not (too) annoying about it either, which is a plus (*ahem* Alice). She's not bubbly like Alice, but she's not aloof and righteous like Rosalie, she's Bella, and just as essential as both Alice AND (CRUCIALLY) Rosalie, in the ineffable, intangible way that she is vital to the family's well-being.