* The name is misspelled. There might be a similar author with a slightly different name.
* The author is not well-known. They might be a self-published author or have written in a niche genre.
* The author is fictional. There could be a character named Shirley Barker in a book or film.
To find out more, please provide:
* Any other details about the author or their work: Do you know what genre they write in? What kind of books are you looking for?
* The source where you encountered the name: Did you see it in a library catalog, a bookstore, or online?
With more information, I can help you find out more about the author you're looking for.