So the king is forcing her to stay around "to protect her", but then sends her to meet the prince, who literally prepared assassins in his own birthday party to kill her. The useless king can't even protect her from a murder plot in his own castle.
Plus, everyone keeps talking about how influential her family is, even though she's completely isolated and her family has apparently withdrawn from the political scene entirely. They're clearly not backing her up at all. The prince had a plan to humiliate and kill her in the middle of his party. Her life was entirely at the mercy of his whims, and he even praises her (in his mind) for being smart by entertaining him so he wouldn't immediately murder her. But apparently her status is somehow an obstacle to him. She's simultaneously considered to be powerful and looked down by everyone. I notice a lot of authors fall into this contradiction with villainess characters. They want them to have a high status background, but they also want them to be pitiful and abused, not willing to accept that it's a contradiction in terms. They want to have their cake and eat it too.