Couple questions.

How do most of her people not know what she looks like? She's got quite a reputation from the border wars alone, not to mention all the traveling she's done with her father. Also the whole blue eyes thing and the fact that it's pretty hard to hide/mimic noble posture.

Also, wouldn't the people rally behind her if only because she was the king's daughter? He certainly would have made life better for the common folk--it was the whole reason he was able to be killed so easily--plus she was a general for like 5 years and a well traveled princess before that so she's going to have at least some level of charisma for rallying the people.