Yeah no. Her fate is scary, but that doesn't mean she gets to take it out on everyone else.
The issue with Anna, is that her motivations are purely selfish. She is treating everyone around her as game-characters, not actual humans. She is giving no care or thought to how much havoc she is causing by doing this. All she is thinking of is me me me.
What she's doing, is not right. Yes. She's in a scary situation and is suffering, but that does not give her the right to ruin the lives of others in an attempt to circumvent her fate. If I was Anna, I would accept it, find solace in talking with people, write down my story and thats that.
Her actions in deciding SHE is more important than the lives and happiness of other people, makes her unsymphatetic.
The writer royally ruined any chance for Anna to be symphatetic in making her totally happy to ruin the FMC and the Prince's life here.
Keep in mind this is a world with magic. Yet the ONLY thing she could think about was "well I'll just fuck over these two people- Oh the prince doesn't love me? Well sucks to be him, we're getting married against his will if need be."
Like I get its SUPPOSED to be symphatetic and why. But its not.
If the writer WANTED to make her symphatetic, we would have to see some effort from her part to figure other options out. Talk to people. Research. Not once have we been told she CAN'T tell her situation to others. Not even a random sidesentence about how "they'll think I'm nuts!" Nothing. Its just as if she cares not for anyone else's life but her own. Ew.