Relationship, commitment--whatever you may call it-- those were never in Nina's list of priorities. It's not that she does not believe in them, it's just that she thinks she's not meant for it. She's loyal and focused only to her cause, helping farmers and doing her best to contribute to the improvement of her beloved profession. And she's always been happy and contented. So when Kristoff came into her life, she thought that there's simply no room for him in her life. Not in the way he wants to be. But he seems so determined to change her mind.