The Wikipedia article on Marie Antoinette is surprisingly interesting. I was an ignoramus going in, but now I know that "Let them eat cake" was really "If they have no bread, let them eat cake," and that she didn't say it. Instead she said something less flip and a little bit more sensitive, about the bread shortage that was underway when she was coronated:

It is quite certain that in seeing the people who treat us so well despite their own misfortune, we are more obliged than ever to work hard for their happiness. . . . I shall never forget the day of the coronation.

Also learned the interesting fact that she and her husband couldn't figure out how to have sex for seven years after their wedding—until they were in their early twenties, that is.

During the Terror, the angry mob comes to her house:

In the early hours of the morning, the mob broke into the palace. The queen's guards were massacred. She and her ladies-in-waiting only narrowly escaped with their lives before the crowd burst in and ransacked her chambers. They made it to the centre of the palace; the king's bedchamber. . . . By this time, a large crowd had gathered in the palace's courtyard and were demanding that the queen come to the balcony. She appeared in her night-robe, accompanied by her two children. The crowd demanded that the two children be sent back inside. So the queen stood alone for almost ten minutes, whilst many in the crowd pointed muskets at her. She then bowed her head and returned inside. Some in the mob were so impressed by her bravery that they cried "Vive la Reine!" ("Long live the Queen!")

I won't give away the ending, but it's rather good—you should take 40 minutes or so to investigate it yourself.