Thanks for that. I also found Mrs Smith to be quite interesting. It looked to me like she fully intended to subtly blackmail Mr Elliot by showing her connection to Anne and when it looked like that would not be effective, she played the protective friend.
I was always a bit unsure about her in the end and it coloured all my first impressions of her in the story.
But it's nice to have one of those characters that you can't paint black or white by the end of the book.