what is the significance of the section where nancy teaches a neighbor's kid how to bake a pie? and what does the pie symbolize?

The pie symbolizes the American Dream......... "It's a American as apple pie."

The significance of this section also has to do with the American Dream; those who've achieved it through hard work, those who want it, and those who are willing to murder for it. Nancy is the perfect example of the All-American girl; she goes to 4-H, mentors little girls, gossips on the phone, and like boys. That's the significance...... who she is, and the fact that even she can't be protected.