The three of them that lived at Versailles --- I think there was a fourth, Clothilde (?), who became a nun --- were responsible for a great deal of Marie Antoinette's early misfortunes. They primed her to oppose Mme. DuBarry, thereby incurring the displeasure of Louis XV, and they worked both ends against the middle, pretending to be her friend and at the same time speaking against the Austrian alliance.
And yes, they skipped France almost as soon as the Revolution began. I have always thought it was a measure of Mare Antoinette's essential sweetness of character that she was concerned about them and their fortunes until the very end of her life.