I've enjoyed all of Julia Quinn's Bridgerton books. Eloise is one of the middle siblings of eight. When she begins a correspondence with the widower of a distant cousin, she never thinks it will develop into a relaitionship. At twenty-eight she feel she might be a confirmed spinster, but that's only because she's turned down sixc proposals already, determined to have a love-match or nothing at all.
Sir Phillip Crane feels that a twenty eight year old spinster might be desperate enough to marry him. He's not looking for a love match. He needs a mother for his two unruly children and that's about it. He's clueless, of course, but it's not all lighthearted froth. Phillip's first marriage was a nightmare. His wife's illness has left him traumatised. He's dumbfounded when the spinster who turns up on his doorstep is not a drab. Eloise's practical good sense saves the day and as their relationship develops you really want to root for them.