SONATA actually didn't hate Princess Mikaela.
After all, she didn't see the princess as a threat.
[If anything, Princess Mikaela is just like an overgrown child throwing tantrums because she doesn't know how to regulate her emotions.]
"Why are you asking when House Hexford won't support me anyway?" Princess Mikaela asked when she regained her composure. "Diether doesn't care about politics, but he'll support my brother because my brother owns the resources he needs to find Celeste Montali."
"Resources?"
"My brother, the Crown Prince, is being supported and endorsed by the Avari Temple," the princess explained. "Diether needs to maintain a friendly relationship with the temple because he needs to stay close to the saintess. Do you know why?"