Bythewood attended UCLA's film school, where she also ran competitive track. At UCLA, she received the Gene Reynolds Scholarship for Directing and the Ray Stark Memorial Scholarship for Outstanding Undergraduates. She graduated in 1991. Along with her friends Mara Brock Akil, Sara Finney Johnson and Felicia D. Henderson (also a UCLA graduate), she endows The Four Sisters Scholarship.
She directed The Secret Life of Bees which was adapted from the best-selling book by Sue Monk Kidd. It was released by Fox Searchlight in October 2008, and debuted at the Toronto International Film Festival and Urbanworld Film Festival that same year.