Character Role Analysis
Although we learn at the end that Captain Wentworth's character arc has been just as complicated as Anne's, we get most of the story from Anne's point of view. If Wentworth had married Louisa, it would be Anne's reaction that we'd care about. Anne's tendency towards passivity, however, separates her from the standard-issue protagonist: in general she doesn’t make events happen by taking action, but instead responds to things that happen around and to her (for example, Louisa’s jump or Wentworth’s letter). Still, Anne forms the lens through which we see those events, and their impact on Anne is what forms the interest of the story, strongly suggesting that Anne is indeed the protagonist.