There was another author famous for this sort of thing in the U.S. recently - in his case he wrote the book as a memoir with no indication that it was other than a journal of his tortured life. Trouble found him when his book made the ever-publicized "Oprah's Book Club" and he was exposed soon after (
story here) and the book turned out to be largely made up. In that case it was a matter of outright fraud, I think, AND that he had shamed the monument to all things literary and American while being such a sneak [poor Miss Winfrey] made it all seem much worse. But the selling of the book itself
was a lie (while no one has ever argued, before or during or after the dust storm, that it wasn't a well-written and compelling tale). But selling the contents of a book as truth, author aside, is a different matter than the overall sounds of this situation.
In the case of an author crafting a public image using any sort of public disguises, embellishments, false bios and so forth is nothing new, as mentioned. So often the mysterious persona of an artist helped sell his/her "art" and it has been fair game for a very long time (George Eliot comes to mind) and even the more recent bestseller "Primary Colors", which became such a craze NOT for what the book actually contained but much more because everyone was trying to figure out who wrote it, is another example. Once it was made public who the author was the book was largely considered unimportant thereafter. So, anyway, I think the author mentioned in these adventure books (and I'm not familiar with the stories/writer, either) is no worse than generations of writers before her. Times have changed, too, don't you think? Nowadays no one would blink if the real author had two heads and was a staunch hermaphrodite!
Knowing if that were the case, though, is dull.
Wondering if it might be, on the other hand, sells those otherwise nondescript novels like hotcakes

. Which is not to say, mind you, that her books are nondescript as I'd never heard of her/them before.
And, of course, that's only my opinion...