The Diary of Miss Idilia

True story or literary hoax? It's in the memoir section in Britain's now-only book chain, and nothing on the cover indicates it to be fiction. Yet, flicking through it, I couldn't help but feel it looked far too literary to be the genuine diary of a seventeen year old girl. By which I mean no disrespect toward seventeen year old girls, or, indeed, their diaries. Being the suspicious sort, I did a little research, but am none the wiser - in fact, all I've really learned is that a lot of other people share my doubts. Now call me macabre, but I am only interested in this if it is the bona fide article; anyone have insider information on this puzzle?