I like this princess.
At first I'd thought the cold stare was because she liked our cute black haired lead but it seems it was a glare caused by a perceived slight and perceived rude behaviour of inviting an unwanted guest. 
The fact she's standing up for what she deems as multiple insults to our mc is amazing (and that she's smart enough to analyse quite quickly what makes sense and what doesn't while the younger sister shoves her foot in her mouth ) . What a fantastic scene.