Mr. Darcy's Secret by Jane Odiwe

One dark secret can completely ruin a bright future...
 After capturing the heart of the most eligible bachelor in England, Elizabeth Bennet believes her happiness is complete--until the day she unearths a stash of anonymous, passionate love letters that may be Darcy's, and she realizes just how little she knows about the guarded, mysterious man she married...

In this Pride and Prejudice sequel, we find ourselves back at Longbourne, witnessing Mrs. Bennet extol on her two eldest daughters' fortunes of landing respectable and well-to-do husbands.

Lord of Scoundrels by Loretta Chase

Sebastian Ballister, the notorious Marquess of Dain, is big, bad, and dangerous to know. No respectable woman would have anything to do with the "Band and Blight of the Ballisters"--and he wants nothing to do with respectable women. He's determined to continue doing what he does best--sin and sin again--and all that's going swimmingly, thank you...until the day a shop door opens and she walks in.
 
Jessica Trent is a determined young woman, and she's going to drag her imbecile brother off the road to ruin, no matter what it takes. If saving him--and with him, her family and future--means taking on the devil himself, she won't back down. The trouble is, the devil in question is so shockingly irresistible, and the person who needs the most saving is--herself!