Of course, what is fascinating about this novel is that the central protagonist is actually dead and looking down on the action from her heaven. However, we can tell from the way that she is introduced, that although she spends much of the time observing and narrating the action of her family and others, Susie is someone that likes to think of her self as a non-conformist. Consider her introduction to herself that she gives us at the beginning of this excellent novel:
In my Junior High yearbook I had a quote from a Spanish poet my sister had turned me on to, Juan Ramon Jimenez. It went like this: "If they give you ruled paper, write the other way." I chose it both because it expressed my contempt for my structured surroundings a la the clasroom, and because, not being some dopey quote from a rock group, I thought it marked me as literary.
She is also clearly presented as a very loving daughter. She shares the same kind of ambitions and dreams of any teenager her age, and thinks about what life will be like when she grows up. She has the same kind of crushes, too. Also, she seems to be very close to every person in her family. She and her father share building ships in a bottle. She is close to her sister and also acts as a secondary mother to Buckley. She seems to instinctively understand her mother and her various needs.
During her return to earth, when she inhabits Ruth's body, she is able to fulfill her desire to kiss Ray. Also, interestingly, at the end of the novel we see Susie's pleasure and delight as she observes her family recover from her death and building themselves a new future which excludes her:
Samuel placed Susie on a blanket near the flowers. And my sister, my Lindsey, left me in her memories, where I was meant to be.
This clearly shows a significant maturity and acceptance of her position as a dead person, relegated to the crowds of the "forgotten." It also shows selflessness, as Susie knows that the only way her family will heal themselves is by moving on and dealing with her perpetual absence.