Jacqueline Bouvier: An Intimate Memoir

John H. Davis, Jackie O.'s first cousin and author of various acclaimed Kennedy bios (The Bouviers, The Kennedys), neatly traces her life to age 24, when she married JFK. He begins with soft-focus, ascot-wearing memories of their ''charmed'' childhood summers together on the Bouviers' lavish East Hampton, N.Y., estate. Davis is especially insightful on the topic of her parents' ugly — and very public — divorce. It was then that Jackie, 10, a straight-A student and prizewinning equestrienne, lost some of her youthful high spirits and became known instead for her legendary ''secretiveness.'' By adolescence, Davis stops relying on ''intimate'' knowledge, and Jacqueline Bouvier: An Intimate Memoirbecomes a more distanced but still informed biography. By the time Jackie becomes a Kennedy, however, Davis seems to throw up his hands, allowing his subject to fade glamorously — and unknowably — into history. B