A poor, plucky young woman (Reese Witherspoon) sets out, with nothing but confidence and her charming smile, to better her life in an early-19th-century England flush with wealth and exotic influence from colonial India. Director Mira Nair (Monsoon Wedding) adorns Thackeray's novel about Becky Sharp, who manipulates her way into Britain's upper crust, with rich sets and costumes and an appealing cast (especially James Purefoy as Becky's one true love). But the effort to turn Witherspoon's Sharp from Thackeray's ruthless schemer into a likable ''modern feminist character'' (as Witherspoon mentions in one making-of doc) renders the visually sumptuous Fair hardly more substantial than a Pretty Woman swathed in silk. EXTRAS ''The Women Behind Vanity Fair'' is a celebration of the largely female cast and crew: ''When you're in a situation...only women can understand,'' gushes Witherspoon, ''it's nice to be around a female director and...female producers.'' Seven deleted scenes include a heavy-handed alternate ending, and in her honey-smooth audio commentary, Nair explains that she cast Gabriel Byrne as the dark Marquess of Steyne because she loves the mystery of his face: ''He brought a soul to an otherwise soulless character.''