@lunectar:
I was reminded of those too. I have more complicated feelings about this case, though. In "villainess" stories the fact that the protagonist should be (at least relatively) nice, yet everyone should think's she's awful, is one of the central conceits of the genre, so I generally let that particular pass without much examination.
It's definitely true that following the rules of being prim and proper is often at odds with being nice—she's like the young adult version of that terrifying grandmother matriarch that has both the fear and respect of everyone. That sort of pressure places burdens on both the person who is "maintaining appearances," and those around them, and I honestly think it's generally a bad idea in that respect. And such people are not pleasant to be around, as a general rule.
But might nobility sometimes have good reason to put on those sorts of airs anyway, despite it making no one happy, because it's a useful tool in the unavoidable games of power-play? That's certainly possible.
In the end, I'm stuck on her harshness: Even if I can sympathise with her in the hypothetical, I still think she's not
quite likeable to me if she's going to hurt people so badly with her words, as she seemed to be making good inroads to doing to the poor nervous lass this chapter. At some point, you need to realize what effect your words are having on people. But I don't fully understand her yet (not enough information), so I might well change my opinion again.