] We don't have to go through any of these horrific trials to be a heroine - just getting through our daily lives with our self-respect and morals and honor intact make us heroines. And this is what Catherine learns.

Extremely well put! Merely to add something to what you've said: the resolution of NA comes, IMO, at the point late one Saturday night when someone unknown arrives, and Catherine goes to her room:

`...a slight motion of the lock proved that some hand must be on it. She trembled a little at the idea of anyone's approaching so cautiously; but resolving not to be again overcome by trivial appearances of alarm, or misled by a raised imagination, she stepped quietly forward, and opened the door. Eleanor, and only Eleanor, stood there. Catherine's spirits, however, were tranquillized but for an instant, for Eleanor's cheeks were pale, and her manner greatly agitated....'

At this point, Catherine has overcome the alarms caused by her `raised imagination' and expects nothing outrageous. But it is, in fact, a horror that is in store for her -- but a real, ordinary, everyday one.