The fact-based drama has Stewart playing Savannah Knoop, a young woman who spends six years pretending to be the celebrated author JT Leroy until the scandalous revelation that this was a literary persona invented by Knoop’s boyfriend’s sister (Dern), who actually wrote the novels. The film is written and directed by Kelly (King Cobra, Welcome the Stranger) and co-written by Savannah Knoop, based on Knoop’s book about her experiences “playing” LeRoy.
I've known this story for a while, and I still get confused every time I read the synopsis of the book/movie.