Becoming Lucy (2017)

Lucy, a pretty brunette 15 year-old, is having a hard time dealing with the fact that her father left her mother for a much younger, and blonder, woman. When Lucy finds out her crush at school likes blondes, she decides to dye her hair so he will like her. But her dyeing job doesn't work so well and she is humiliated by her crush's girlfriend. While she is feeling awful, her English teacher opens up her eyes to her writing talent. She then finds out that her mother never really gave up on her dreams of being a writer, and realizes that her father leaving was neither hers nor her mother's fault.