] My questions refer to S&S and Eliza's divorce with Col. Brandon's elder brother.

You might also look for the book Broken Lives: Separation and Divorce in England 1660-1857, by Lawrence Stone (Oxford U. Press, 1993). I bought this book a few months back and haven't had a chance to read it yet, but judging from the table of contents, I think it might have a lot of the info you're looking for.