Yes, Marie-Antoinette is very much a supporting role in this.
Marie Antoinette really comes as a supporting role
Speaking of Marie-Antoniette, there's a nice little detail in the movie where Diane Kruger (as M-A) stands near a famous, real-life portrait (or a high-grade facsimile, in any event) of the real Marie-Antoinette.
Yes! ...and so you see the little resemblance of the chubby face of the real MA compared to the angular, model like features of Kruger. A miss, i think...