Looking for a story

I'm trying to find a story that I read some time ago, and I can't seem to find it anywhere. I know that Mr Bennet was a lord and a widower--I believe he was also ill for much of the story (a heart problem, I think). Elizabeth was either his only child or the other girls weren't in the story much. I think they also might have had a different last name. I'm fairly certain that I read it here.

Does it sound familiar to anyone?