We are seeing Catherine maturing as a character. She is young and from a very small town with limited acquaintance. As noted by previous posters, she grew up in a family that was honest and sincere, not given to hyperbole and false flattery. This is her first venture out into the world, and unfortunately, part of that process is learning that there are very different types of people with different levels of trustworthiness. By gaining experience, she is gaining insight and judgment. I think that we will see this maturation process continue as the novel progresses.