It is the familly tree  
:
http://www.madame-royale.de/en/picdat/tree.htm
There is a legend who said she was replaced by her sister, but it is the firt time I heard this story  :
http://www.madame-royale.de/en/index.htm
The legend of Spohie Batta, the "Dark Countess" is currently being put forth by supporters of the descendants of Naundorff as the reason why the Duchess of Angouleme did not recognize her "brother." It is not a new story, and was circulating during the Restoration. People could not understand how the sad, nervous, tense woman, prone to fainting spells, could be the daughter of the beautiful, charming, vivacious Marie-Antoinette. There was not the same understanding of post-traumatic stress syndrome as there is now, or survivor's guilt, common to those who are the sole survivors of a family disaster.
No one really knows what exactly Marie-Therese was subjected to in the Temple when she was in solitary confinement for a year. The "memoirs" she wrote there were written under the surveillance of a revolutionary spy; Marie-Thererse later disowned them. (Changing the "story" is also common to those who have been through trauma, as over the years they come to remember more that they blocked out and understand more about the implications of the terrible things that occurred in youth.) Before Mme. Elisabeth was killed, she begged Marie-Therese never to let the guards find her undressed or in bed. Since the guards would make surprise visits to her cell at all hours of the day and night, the 16-17 year old princess, Madame Royale of Versailles, would sometimes spend the night in a chair, terrified. (See Memiors of the Duchesse de Gontaut)
When restored to France and the Tuileries in 1814, Marie-Therese wanted everything to be exactly as it was when she had last been there with her family, which was of course, impossible. She was subject to nightmares and hysterical episodes when something would by chance remind her of her family's ordeal. She tried to reverse the gossip about her mother by her own excruciatingly correct deportment and charitable activites, preferring hospitals and orphanages to the ballroom and the opera box, but due to propaganda people by 1830 she was called "Madame Rancune" or "Lady Resentment."
She was haunted by the fate of her brother and never certain that he had died in 1795. A funeral Mass and day of mourning was held for her parents, but there was never anything for Louis XVII. But that is a subject for another discussion....
She never had any children due to her bizarre and unhappy marriage, but loved her niece and nephew, Louise d'Artois and the Comte de Chambord, as her own.
