I agree that Edmund and Mary would have been miserable in the long-run, and Edmund was more in love with what he believed she was than Mary herself. However, Edmund was still in denial at the beginning of Tom's serious illness. I would have thought that her reaction to that would have been enough of an eye-opener, but it wasn't until Maria and Henry that he figured it out. To be fair, the reason that Mary wished for Tom's end was so she could have it all: Edmund (who she does love) and the social status that she wanted. It was not his death, but Edmund's elevation that she liked. Still...Edmund must be as dense as a post or Mary must be really lovely.
