Alicia has to take care of her family, including her father, while trying to go to school. She is afraid of the mice, and the mice are really symbols of her economic level. Mice are low on the food chain and the vermin of society , just as Alicia and her family. Alicia does not want to be stuck in the life she has now, feeling small and powerless.
Well you read in the chapter that she has taken on her mothers roles because she has died, but her father has made her take on more rolls then you would anticipate. Four-legged fur is symbolic which represents her father. Her father is having rapping Alicia in the bathroom. When Alicia talks to her father about this he merelly says "close your eyes and they'll go away, or You're just imagining."