The Blessing by Nancy Mitford (1951)

Grace ends up marrying dashing aristocratic Frenchman Charles-Edouard after being swept off her feet while her slightly drippy fiance was away at war. It proves to be a good step, on the whole. She is immediately completely taken with his house in the south of France, Bellandargues. They spend an idyllic period there with their new baby, a little boy, and of course his extraordinarily firm, calculating and slightly dour English nanny, who provides some fabulous comic moments. Then comes a move to the Paris house and reconnection with Grace's old schoolfriend Carolyn, who has married a wealthy American with a love of the sound of his own voice. Their boy, Sigi (short for Sigismond), now a little older, is consistently shunted to one side as they embrace a life of society and all its outre goings-on. Charles-Edouard's typically French roving eye finally undoes him, as Grace realises she can't be quite as easy as she'd originally hoped with his philandering. Thereafter, Sigi is spoilt rotten by his separated parents, one in France, one in England. He realises, little blessing that he is, that this is the way to keep things, and deliberately foils all attempts at a reconciliation. In the end, he is himself foiled, but not before several classic schemes have come to fruition. Mitford's prose is sparking with wit, full of wry-mouthed worldliness. All her novels thus far have been so, and the unnatural division pushed forth popularly between the 'bad' first four and 'brilliant' second four is a nonsense.