
I guess you've never read shoujo manga then? :P Because a lot of shoujo MC's are like that. They're meant to be a fantasy for young girls. Which usually lacks any real logic.
It just so happens that this manga shows us what would realistically happen if you have a girl like that suddenly enter nobility. There's also something that's been hinted at in the previous chapter that'll take it even a step further. But I won't spoil that in case some people haven't realised/read about it yet.

Well, if you really want to know... *SPOILERS AHEAD*
I don't know the details really, but I've heard from several other sources that Yuri is revealed to be a spy of a neighbouring country. And I personally wouldn't be surprised if the second prince's infatuation and her seemingly incredibly naive and stupid ideas to change the kingdom for the better is in fact part of a plan from the neighbouring kingdom, though I haven't heard anything about that yet.

Haha, of course I read shoujo, but after some time u know something is up with her, and that all this smiling and acting cute is just fake. And I really get mad, when I saw her charming everyone in her group. ARRRGH, just remembering makes me furious. :D
I dont hate the shoujo girls in other mangas cause their just natural pure hearted and ridiclous in their thinking. ;) But Yuri is fake. :D

I mean it make sense. She's intentionally doing those things (Expensive gifts from the fool, spending so much money, and even going so far as to take away the military well that last part is more like attempted) in order to weaken the kingdom that are still suffering from the war thirty years ago. Obviously I think we know what is going to happen next (〜 ̄△ ̄)〜
Whenever I see Yuri smiling and acting all cute I just want to punch my screen. I hate girls like her the most. (╬ ̄皿 ̄)凸