Your first sentence, Mandy, prompts this response. Perhaps I'm straying into "Austenuations" territory here and this will need to be deleted, but I think my idea is relevant to this GR.

I see it as similar to Charlotte and Mr. Collins in P&P. Anne could have married Charles and would have made the best of the situation. But, also as in P&P, Anne did not accept Charles, as Elizabeth did not accept Mr. Collins, because she knew he could never make her happy (not to carry the comparison too far: Charles is certainly NOT Mr. Collins, of course!). Although I think Anne might have had a measure of happiness with Charles, it would be an unequal match, in either case.