I would say that the rising action point of the novel is chapter 10. This is where Jesse thinks about his new found abilities to believe in himself. It is also where he enjoys the guilty pleasure of going to an art gallery and museum with his teacher, Miss Edmunds.
Jesse has grown so much as an individual under Leslie's influence that we can see him existing as his own person without her. It is a crushing blow at the end of the chapter when Leslie's death is clumsily announced by Brenda-
“Your girl friend's dead, and Momma thought you was dead too.”