Hi Drummergirl,
This is a wonderful story. The tone is formal. It suits the story and plot very well. The reader is wondering if Karla will avoid dealing the the zombie apocalypes. They will read to the last word to find out. The plot is straight forward and moves along logically. In the story, a girl tries to get away from zombies who have overrun her home town. The conflict is well defined. there is no doubt about what is going on here. The characters are well developed and believable. They come across as real people. The dialogue is well done and realistic. The characters speak like real people. The description is detailed and vivid. It puts the reader all the way into the story. I did come across one structural issue that needs your attention:

1)You have used dialogue but neglected to put each piece into its own paragraph. You should remember to consistently do this to keep your writing clear for your reader.

The story is consistent in terms of point of view and tense. Great job.