How we cite our quotes:
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.
"You're a good kid. I think you have a lot to say. I'd like to hear it." (56.16)
Mr. Freeman is the only one who offers to listen to Melinda. This does a lot to break through her isolation.
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.