One of the many false rumours that surrounded Marie Antoinette at the end of the l'ancien régieme was that the Queen indulged in several lesbian affairs. The rumour often placed the Princesse de Lamballe or the Duchesse de Polignac as the Queen's mistress mainly because they were the Queen's best friends.
That the satirists chose the Princesse de Lamballe as the woman Marie Antoinette should have had a romantic relationship merely shows how little they actually knew of the women. The Princesse was notoriously prudish and refused to take indulge in any affairs - with men as well as women. It was the widespread rumours of lesbianism that would contribute to the horrifying death of the Princesse.
At the time homosexuality was known in France as the "German vice" which was used as a solid reason for why the Austrian-born Queen had to have at least a streak of homosexuality - she was born with it!
Marie Antoinette had been completely starstruck by the Duchesse de Polignac when she met her and the Queen's admiration was interpreted as being yet more lesbian affection. The fact that Yolande was made a Duchesse shortly after meeting the Queen gave life to the rumours; after all the Sun King had been famous for bestowing lofty titles on his favourites!
When the storm of the revolution had passed a certain noblewoman by the name of the Countess Lamont returned to France where she quickly claimed to have been the dethroned - and beheaded - Queen's mistress. Of course by then all the danger was over so the Countess risked nothing.