I found a couple of interesting remarks about Princess Clothilde from the "Life and Letter of Madame Ellizabeth de France...
The difference in the characters of the sisters made a difference in the feelings of their governess towards each. Jealousy came to increase the asperity of the younger sister's nature. "If Clotilde had asked you," she said, one day, when Mme. de Marsan had refused a request, "she would have had it." [Page 4]
"Clotilde was born with the happiest disposition, which needed only to be encouraged and aided."