Who is Jenny from Reckless and what is their importance?

Jenny is described throughout the narrative as being "nice". Sensitive and generous-spirited, particularly towards her roommate Callie (who used to be dating Easy, the young man Jenny is now involved with), Jenny is often bewildered by events and attitudes around her. She is a bit of an innocent, a bit of a babe in the woods, and is easily hurt, easily taken advantage of, and somewhat hesitant about standing up for herself. Eventually, however, after the experiences of the party and after seeing Kara stand up for herself with the obnoxious Heath, Jenny seems to realize there is at least the potential to, and reason for, developing more of a backbone. The final moments of the book seem to suggest she will.