Although she is not present in the novel very frequently, May Wynn affects almost every event of the story. Like Willie, May does not think much of their relationship in the beginning of the novel, but she cannot let it go when Willie leaves for sea. She is less reserved than Willie is, directly confronting him with the difficult truth about her feelings. When she kicks Willie out of the car in front of Furnald Hall, she suggests that she wants either to marry Willie, or to cut off all contact with him. Because she prefers the option of marrying him, May gives Willie a chance to recognize how special their relationship is.

In Yosemite, May's conscience plagues her. The novel sometimes delves into her consciousness, revealing that May might have planned exactly what Mrs. Keith later suspects: to sleep with Willie in the hope that it will trap him into marrying her. When Willie proposes, however, May's conscience does not allow her to accept him. At the end of the novel, there is a suggestion that May Wynn will accept Willie's marriage proposal, which has become the wholehearted, guilt-free pledge of love that she always wanted from Willie.