Princess Cyd (2017)

High school athlete Cyd Loughlin lives alone with her depressive father in South Carolina, perpetually longing to get away from it all. When her aunt, famous novelist Miranda Ruth, agrees to host her for a few weeks during the summer, Cyd jumps at the opportunity. While there, she falls for a girl in the neighborhood, even as she and her aunt gently challenge each other in the realms of sex and spirit.

Source: TMDb