A fantasy book I read in third grade in 2011-2012 in extremely specific detail! mean prince and peasant girl

So the story is about this horrible prince, he is about to become a king and his father who is very old and is on the brink of death, he loves his son very much, but the prince just doesn’t care about him. And the story is also about another character, she is like a peasant and she had a really nice dad, but he already died, but the point is that she can talk to animals especially this white or gray wolf. (she is also described as a complete opposite of the prince)

After the king dies, the prince is appointed to as king, I remember one of the subplots was about some guy who was in the royal court and gets in trouble by the new king, and then what happens is one of the most graphic scenes I read as a child, it was a scene where the author describes the royal court guy whose wound that is literally rotting and being eaten by rats, I don’t remember if he dies or survives. But the new king would constantly threaten his royal court members that he would throw them into prison to die and be eaten by rats.

More stuff I remember is that at one point, the new king meets the gray/white wolf and I guess sometime in the book the new king almost dies in the prison or in a winter storm, but he meets the peasant girl this way, she rescues him and nurses to health If I remember correctly, I feel like he was still mean to her and she was very patient towards this horrible person. At one point these two get separated from each other and I don’t remember anything else from there. They did fall in love with each other and marry later at the end of the book.

I can tell you that I do remember what the cover of the book looked like, it had some brown, red, darkish green tones, very warm green and brown forest colors, both characters were facing each other side profile, the prince had like longish brown hair to his shoulders and the peasant girl had a lovely green dress with a brownish cape she had long brown hair with a headband medieval style that was seen on her forehead, I also remember she had a belt that had a long trail down her dress. I remember that they were in a room and the outside was winter, the wolf was also on the cover possibly with other animals and bugs as well. The style of the cover was semi-realistic while the animals were drawn realistically, it was also a short story it wasn’t that big of a book.

I hope this will get answered I remember this book fondly, thank you.