If the success of Sarah proved anything, it was this: you too can be a best-selling non-fiction author as long as you're willing to write fiction.
Consider the case of JT Leroy: a "real" imaginary transgendered truck stop hooker who became imaginary addicted to "real" drugs. His life story was a huge success: Oprah pimped it to millions of her slavish book club automatons.
Unfortunately, it was all a lie: JT Leroy was really Laura Albert, who employed friends and relatives to portray Leroy at live appearances. A film company that bought the rights to another of Albert's novels, "Sarah", was not amused: they sued Albert. But her defense attorneys have made their defense, and boy, it's a doozy:
She was found guilty, but her reaction is pure craziness: a high-pitched temper tantrum about the rights of artists to adopt pseudonyms for creative reason. They may very well have that right, but signing legally binding contracts under an assumed name, without ever disclosing to the other party who you really are? I seriously doubt it, you crazy broad.