Well there's 2 seasons worth of character development thrown right out the window. Considering how easily this mangaka kills off main characters (like even more ruthless than Isayama for AoT because you kinda get desensitized towards AoT deaths by midway), I should've expected it
Not only has she gradually wrapped prince bro around her finger, but now all the servants follow her willingly because they have seen with their eyes that she serves as a leash for prince bro's violent tendencies
She could literally fart and the empire would be like, "Sasuga Mia-sama for creating another form of cheap sustainable energy!" or some sh*t. But she wouldn't because Mia is the Empire's wisdom and a girl and girls do not fart
I like to imagine that when prince bro does eventually find out that ML is actually FL, he'll be like "you were a WOMAN the entire time? Reality is often disappointing"