Persuasion

I'm in the middle of Jane Austen's Persuasion right now and I'm a little confused. I'm just losing track of who people are. I'm only on like chapter 5, but Anne and Mary just went to visit the girl's of the Great House. So who exactly is Mary? Anne's sister? and what was all that about the guy that Anne almost married. Is that who is renting their house? The Musgroves I think. And I haven't quite figured out Anne yet. She seems kind and quiet at times, then not at others. And her family seems like loud mouth jerks. I guess I'll figure it out. I hope.