La Duchesse, I don't know if you are still looking for these answers or not. I'm sorry that I came to your post so late
For details on a gala at Versailles, the memoirs of Madame Campan are a good place to start, I should think.
As to your questions about the nobles during the revolution; you must keep in mind that the revolution was a very long, complex event covering 10 years. Of that time, the Reign of Terror lasted not quite 2 years---1793-94 (it was during this period that people were arrested and guillotined). The Revolution began in 1789, so the nobility had almost 4 years during which they could leave France of their own free will before they really had to worry about losing their heads. Most of the nobility did leave. Madame de la Tour du Pin wrote in her memoires that by 1791 it had become a "point of honor" for the nobility to leave France, rather than tolerate any further insults to their dignity. They immigrated or fled to all parts of Europe. A large number of them went to Switzerland, others to Italy, some to England, and even as far as Russia and the Americas. Those who chose to stay in France generally fell into 2 very small groups: the ones who were sympathetic to the revolution and supported it (like the Comte de Mirabeau & Duc d'Orleans), and those who continued to serve the King in some manner---courtiers, officers, ministers (Princesse de Lamballe). It was these two groups which were caught in the Terror. Even then, not all of them were arrested or guillotined. Some managed to be forgotten or ignored (especially if they weren't very important to begin with), others managed to make friends of the revolutionaries, and still others went into hiding (like Madame de la Tour du Pin). The ones who were caught, were those few who, to put it frankly, ignored the writing on the wall (Josephine de Beauharnais).
I might add, that it was never a crime during the Terror simply to be a member of the nobility. This is a popular myth. Noboby was arrested for being noble. Those who were arrested, usually were people who either had served the King in an important position, or else were caught communicating with friends and relatives who had already left France; which was seen as treason during the Terror. During the "High Terror," simply being related to somebody who had left France was enough to earn a death sentence. But as I said, the majority of the nobility left France before this happened.
