Sara Louise, who goes by “Louise” or “Wheeze,” is the protagonist and narrator of the novel. She is older than her twin sister by a few minutes and believes that she has been neglected ever since Caroline was born weak and sickly. Louise describes herself as tall and big-boned, with dark hair and strong features. She particularly obsesses over her hands, which are rough and cracked from crabbing.

Louise is imaginative and romantic, particularly as a teenager, who dreams of escaping the small island and falling in love. She is an avid reader of Time magazine, even though she does not always understand what she reads there. She keeps many of her emotions to herself, though they sometimes erupt in violent ways, as when she hurls her bottle of hand lotion against the wall when she finds Caroline using it. Her deep feelings sometimes cause her embarrassment, as when her classmates ridicule her suggestion that Christmas should be canceled after the Pearl Harbor attack or, more profoundly, when she develops a schoolgirl crush on the Captain and comes to view her relatively innocent feelings as cause for shame and sin.

Throughout most of the novel, Louise, who identifies herself with the biblical figure of Esau, an older son robbed of his birthright by his younger twin Jacob, is resentful of the attention and care her sister receives.