Angelbuck3, there's some great stuff here! You begin with conflict, and with short sentences that reflect the urgency of her movements. You introduce both character and setting, and you put the reader right into the action. My comments are few and minor:
angelbuck3 wrote:She shivers against the cold on her skin; the sharpness of it stings the back of her throat with every breath. The snow is falling thicker, faster now. The flakes land on her skin and almost burn before they melt. (the idea of snow 'burning' is slightly cliched; I've read it before.) She wonders when they(when you use this pronoun, the reader assumes that it refers to the most recent noun--in this case, the snow flakes. I had to do a mental readjustment when I realized you were talking about this girl and someone else) will stop running or if they will find shelter before sundown.
With each step she takes, the snow crunches beneath her bare, numb feet. She pulls her fur shawl a little tighter around her seventeen year old (I'd eliminate her age here. First of all, the sentence flows better without it. Second, precise age is rarely that important; it can be shown in context clues, dialogue, etc. far more effectively) frame in an attempt to slow her shivering. She pictures her sandals still lying on the floor in their small hut. She wishes she had remembered to grab them in the rush out. (I'd eliminate that phrase; the sentence is more effective without it.)
Most of what I've suggested is optional, though--writing's an art, not a science, and these are style points rather than grammatical issues. Good writing!