None of the memoirs of the period, nor any of the serious biographies of Marie Therese Charlotte support a rape in the Temple Tower. Nor do any documents exist in the French National Archives to support this. But feel free to gossip about it.
At the time of her death, Marie Therese must have felt certain that her brother was dead, or had died in the Temple Tower in 1795. She would not have named the Comte de Chambord her heir, otherwise. Her brother, as the legitimate King of France, would have been named in her will, especially since her money and jewels would also have belonged to him, since it was all that remained of the fortune smuggled out of France by Marie Antoinette in 1791.
She very character, serious and pious, would not allow her to keep her brother's existance a secret if he, indeed, still lived.
In all likelihood, she paid "hush money" to certain individuals to keep the rumors and imposters quiet. Naundorff, as you know, hounded her until his death.
The "secret document" in the Vatican is a myth and is a good example of the rumors and outright lies that can gain credibility as "historical fact" over the years.
I would like to know the source, a reliable cited source, with a referral to documentation that I can look at to support this supposition and rumor that Marie Therese sent a secret document pertaining to the Fate of Louis XVII to the Vatican. Not just , "Oh, I heard....."
I have studied Marie Therese's life for many years, have examined original letters and documents in both the French and Austrian national archives, and have also interviewed members of the Bourbon family. I know what I'm talking about----as others on this site do not.