Is the history in the Marie Antoinette 2006 film correct?

Is the history in the Marie Antoinette 2006 film correct?
Marie-Antoinette was born on this day in 1755, and in view of the new movie about her, it is timely to consider her again - this time to focus on the pesky "Let them eat cake" story. The movie has been criticised for its historic inaccuracies and its focus on the trivia and excesses of her life, but in doing so it is surely only following the precedent of "history" itself, which - being written as is usual, by the victors and propagandists - has not been kind to her. Imagine any 14 year-old girl that you know. Imagine sending her off to another country (where she was not fluent in the language) and marrying her off within a few days to a man she had never met. Give her the huge dual responsibilities of facilitating the diplomatic relations between the two countries, and of providing an heir and preferably also a spare. Imagine this child's homesickness. Imagine her distress at the public ridicule she endured for not immediately producing an heir when the real reason was that her marriage was not able to be consummated until Louis submitted (years later) to minor surgery to correct a minor anatomical "glitch" that had made consummation impossible.
This adolescent spent her first seven years as a virgin royal bride assuaging her homesickness and filling her time with all sorts of fun and games, as any teenager would. She does not seem to have been gratuitously unkind, and motherhood, when it finally happened, and maturity, when the years gave it, made her quite courageous. Marie-Antoinette was accused of many things both during and after her life, for which there is no evidence. It is time to put to an end, once and for all, the malicious slander that she said of the hungry at the gate, when told they had no bread, "Let them eat Cake". The phrase was written when she was a child, in a fable by the philosopher Rousseau who attributed it to a "great princess" to indicate her insensitivity to the poor.
It was appropriated by post-revolutionary publicists and re-attributed to her to support their propaganda. As far as the food depicted in the movie goes, the cakes at any rate are far from historically accurate. "Cakes" in Marie-Antoinette's time were leavened with beaten eggs, or yeast, and were baked in "hoops" supported by paper cuffs and set on flat baking trays - they were not airy, fluffy, butter-cream-frosted, highly decorated concoctions which require baking powders and shaped tins, both of which were developed after she was dead.