To Sir Phillip, With Love by Julia Quinn (Bridgertons #5):

Sir Phillip knew from his correspondence with his dead wife’s distant cousin that Eloise Bridgerton was a spinster, and so he’d proposed, figuring that she’d be homely and unassuming, and more than a little desperate for an offer of marriage. Except . . . she wasn’t. The beautiful woman on his doorstep was anything but quiet, and when she stopped talking long enough to close her mouth, all he wanted to do was kiss her…

Eloise Bridgerton couldn’t marry a man she had never met! But then she started thinking… and wondering… and before she knew it, she was in a hired carriage in the middle of the night, on her way to meet the man she hoped might be her perfect match. Except… he wasn’t. Her perfect husband wouldn’t be so moody and ill-mannered. And he certainly should have mentioned that he had two young – and decidedly unruly – children, as much in need of a mother as Phillip is in need of a wife.