Quote 1
I knew he was going to kill me. I did not realize then that I was an animal already dying. (1.91)
This quote obviously refers to the violence by which she dies, which heavily impacts her experience in the afterlife. It also suggests that her injuries, prior to Mr. Harvey killing her with the knife, are serious enough to kill her.
Quote 2
We had been given, in our heavens, our simplest dreams. (2.17)
The Lovely Bones strongly suggests that when we go to the afterlife, we bring along all our Earthly traits, and we continue to grow and change after we die.
Quote 3
"I could not have what I wanted most: Mr. Harvey dead and me living. Heaven wasn't perfect." (2.39)
Susie isn't in to the whole death thing whatsoever when she first gets to heaven, but she gets used to it one she's realizes how cool it is.