God the big rant in this chapter was just some of the most hilarious self-insert Mary Sue-ing I've seen in a while. The idea that the noble women somehow don't understand the concept of concubines despite the fact that they would have grown up with it being completely normal and acceptable in this society, even going as far as calling it "cheating", is just hysterical. Plus she seems to be acting like political marriages either aren't a thing or aren't well accepted, since as far as I can tell she's assuming that the nobles marry because they love their partner and consent from the person in lesser standing is required.
"Yes you see, I'm going to tell you all things that you should already know and accept as normal, and completely upend generations of an accepted practice as a result of a single rant by some random commoner girl!"
Never change, self-insert Mary Sues, never change. ?