The Nanny falls into the genre of contemporary romance. Although The Nanny deals with serious subjects, such as complicated family dynamics, self-doubt, and child neglect, it is underpinned by lighthearted and comedic moments. Contemporary romances are categorized by their happy endings and familiar plotlines but often focus on the main characters’ personal growth and the obstacles they must overcome to achieve their happy ending. As in The Nanny, most contemporary romance heroines and heroes are flawed; these narratives often show protagonists helping each other overcome barriers to not only becoming romantically involved but also being better, happier people.

Just as contemporary romance novels rely on familiar narrative structures, they also often feature tropes, archetypes, and common situations, such as friends-to-lovers relationships, marriage-of-convenience plotlines, and small-town settings. The Nanny uses many conventions typical of contemporary romance novels, including the forced proximity trope, in which two people who are trying to avoid their attraction to one another are continually forced to be around each other. Forbidden love is another common romance convention used in The Nanny; the clandestine nature of their relationship forces Cassie and Aiden to confront the fears and priorities that prevent them from becoming romantically involved and hinder them personally.