Chapter 5, page 3 is where the Duchess mentions her younger brother will take the position from her (and suggests she will poison him if he doesn't step down).
Chapter 5, page 5 is when the Colonel's inner thoughts reveal that the generals of the 5th division won't listen to the Duchess because she will eventually be ousted
I don't know what will happen going forward, but it certainly seems like the Duchess is trying to shore up her position.