Swapling

Yennefer Hayes discovered that her husband, Lester Hughes, was not only having an affair with her own sister, Vesper Hayes, and had a child with her, but had even switched the babies—hoping she would raise their illegitimate son as the heir to the Hayes family. She immediately took decisive action and switched the babies back. Eighteen years later, at the coming-of-age ceremony, Yennefer exposed Lester and Vesper for their despicable true selves, putting the scumbag and the shameless woman in their place. In the end, she found her happily-ever-after with her senior, Ethan Clarke.