Louisa Musgrove is Charles and Henrietta's sister. She is a headstrong and romantic young woman who admires the navy excessively. Louisa has two important roles in the text. To begin with, she represents the danger of obstinance. At the close of Volume One, this is illustrated by way of Louisa’s accident, which occurs as a result of her insistence that Captain Wentworth jump her down the stairs despite his attempts to dissuade her. Her firmness of mind means serious injury for her and significant guilt for Captain Wentworth. Consequently, he is forced to rethink his initial judgment that “strong character[s]” are superior to impressionable ones. As Anne reflects a few pages later, “she thought it could scarcely escape him to feel that a persuadable temper might sometimes be as much in favour of happiness as a very resolute character.” Here, Austen suggests not that people must always soften their opinions and defer to the will of others, but that an excess of stubbornness may be detrimental, as it hinders logic and practicality.
Louisa also represents a common archetype in romantic fiction: she is the rival who poses a threat to the heroine’s marriage plot, generating tension within the narrative. Scorned by Anne and looking for a wife, Captain Wentworth initially encourages Louisa’s flirtations, much to Anne’s distress. For example, during the walk in Chapter 10, Louisa flirts with Captain Wentworth by saying that if she “loved a man, as [Mrs. Croft] loves the Admiral, [she] would always be with him, nothing should ever separate [them].” Unsurprisingly, Anne is pained by Louisa’s innocent flirtation because it forces her to recall how she and Captain Wentworth were themselves separated. Fortunately, Louisa finds a match in Captain Benwick, and Captain Wentworth realizes he never actually cared for Louisa the way he cares for Anne.