Quote 13
They swallow her whole and she never looks back at me. Not once. (51.21)
When Heather breaks off their friendship, Melinda feels a thousand times more isolated. Her thought here also shows that she sees the Marthas as carnivorous monsters who don't care about Heather.
Quote 14
I guess I'll answer if [David] calls. But if he touches me I'll explode, so a date is out of the question. No touching. (73.14)
This thought reveals how much the rape is threatening to isolate Melinda from potentially excellent relationships and experiences. Since Melinda thought Andy was nice at first, and trusted him enough to be alone with him, she no longer trusts her ability to judge character.
Quote 15
When the pep rally ends, I am accidentally knocked down three rows of bleachers. (13.5)
Translation: Mean kids at the pep rally push Melinda down the bleachers. This is after one girl pokes and knees her throughout the rally. This is an assault. Heather and others who watch contribute by not helping.