There is a Project Gutenburg book: Memoirs of the Courts of Louis XV and XVI. Being secret memoirs of Madame Du Hausset, lady's maid to Madame de Pompadour, and of the Princess Lamballe — Volume 7 (
http://www.gutenberg.org/etext/3882). This in fact seems to have nothing to do with Madame du Hausset or Madame de Pompadour, but rather with the Princesse de Lamballe and includes an account of Marie Antoinette's sending the author (apparently a young Englishwoman) to "Tell my sisters the state of Paris. Inform them of our cruel situation. Describe the riots and convulsions you have seen. Above all, assure them how dear they are to me, and how much I love them." When she arrived in Parma, "I delivered Her Majesty's letter [to Maria Amalia]. Before she opened it, she exclaimed, "'O Dio! tutto e perduto e troppo tardi'! Oh, God! all is lost, it is too late!" I then gave her the cipher and the key. In a few minutes I enabled her to decipher the letter. On getting through it, she again exclaimed, "'E tutto inutile'! it is entirely useless! I am afraid they are all lost. I am sorry you are so situated as not to allow of your remaining here to rest from your fatigue. Whenever you come to Parma, I shall be glad to see you." She then took out her pocket handkerchief, shed a few tears, and said that, as circumstances were now so totally changed, to answer the letter might only commit her, her sister, and myself; but that if affairs took the turn she wished, no doubt, her sister would write again. She then mounted her horse, and wished me a good journey; and I took leave, and set off for Rome. I must confess that the conduct of the Duchess of Parma appeared to me rather cold, if not unfeeling. Perhaps she was afraid of showing too much emotion, and wished to encourage the idea that Princesses ought not to give way to sensibility, like common mortals..............................................
But how different was the conduct of the Queen of Naples! She kissed the letter: she bathed it with her tears! Scarcely could she allow herself time to decipher it. At every sentence she exclaimed, "Oh, my dear, oh, my adored sister! What will become of her! My brothers are now both no more! Surely, she will soon be liberated!" Then, turning suddenly to me, she asked with eagerness, "Do you not think she will? Oh, Marie, Marie! why did she not fly to Vienna? Why did she not come to me instead of writing? Tell me, for God's sake, all you know!"(and so on and on and on).
Whether these are genuine memoires or not, is hard to tell. They certainly have a highly charged romantic air about them, but that was in keeping with the sensibility of the times, and read like Fanny Burney or other late eighteenth century writers. However, the references to the Duchess of Parma and the Queen of Naples are interesting and suggest that whoever wrote them knew of their degrees of intimacy with Marie Antoinette and how they reacted (or might have reacted) to the bad news from Paris. Maria Amalia with expressions of concern but no real feeling; Maria Carolina with a greater degree of grief and sensibility.
