The first half of the book paints a convincing picture of our heroine's privilege and her powerlessness. The machinations that determine her fate all happen elsewhere, at court, only whispered about in the rumors of servants. The settings—her childhood château, the guardian's house in town, the merchant ship, the island—are well drawn. Overall, I found the novel engaging.
My only problem with Isola was the anachronistic attitudes of the heroine and narrator. I found most of the characters' actions to be appropriate for the period (1531 - 1545), but Marguerite's reactions to them are conspicuously modern. The cover of my paperback edition calls the book "a feminist castaway tale about love, faith, and self-actualization"; feminism and self-actualization are twentieth-century notions which would have made no sense to a sixteenth-century noblewoman. I appreciated the times when Marguerite struggled with her faith, and cringed when she demanded respect for things to which she felt she was entitled.