I wonder what is driving her to be like this?
Don't get me wrong, I love an evil woman protagonist, but it feels almost cartoonish, so I'm hoping to see a reason or a goal for this
The prince said they 'endured' her and call her mother insolence, so I think they had looked down on her slightly as child, and only grew to hatred as she acted out due to being looked down as an illegitimate child.
I would love it if the prince and princess are also more complex as characters rather than 'good people who are secretly bad'. But since this is the second chapter, I'll wait to see what happens next.