Alice Keppel, mistress to Edward VII, ``loved profitably'' and with discretion; not so, alas, her daughter, Violet Trefusis, whose liaison with Vita Sackville-West marginalized her for the duration and destroyed her for life. Self-appointed apologist Souhami (Gertrude and Alice, 1992, etc.), has it in for Vita, but her great flair for words finesses the fact that the mot juste isn't always just. Violet disdained the compromises at which her mother excelled and which Vita and Harold Nicholson adapted to sustain both their marriage and their separate homosexual affairs. She found herself irretrievably isolated by her disdain of the conventions of post- Edwardian society; by her mother, who negotiated a scandal-masking marriage for Violet with Denis Trefusis that became a scandal in itself; and worst of all by Vita, her whole raison d'àtre. When Denis died at 39, Violet finally achieved legitimacy as a widow, and she and her mother became the best of symbiotic friends—but that's as happy as the ending gets. As time passed, Violet seemed more ``her mother's camp understudy than the bohemian spirit to which she had aspired.'' She had, Souhami writes, ``learned the script . . . but her performance was caricature.'' (She was ``too intelligent . . . and disappointed'' for anything other.) While Mrs. Keppel embodied the true spirit of Edwardian hypocrisy, it eluded her daughter. Vita, though, got the message from her own mother; because marriage was the socially acceptable cover for socially unacceptable sex, Vita would never live up to her commitment to elope with Violet. If Souhami at once extols and excoriates Mrs. Keppel, she unambivalently punishes Vita; this is ultimately a revisionist Portrait of a Marriage. And she lets Violet go almost uncritically, viewing her as a victim, when events could be read to portray her as more manipulative and active than Souhami allows. (24 pages photos and illustrations, not seen)