Whois Penny?

Penny is Maddie's best friend, but their relationship is rocky from the beginning of the novel. Penny was a great lacrosse player until she got cancer. She was not able to play anymore, but was invited into popular girl Bitsy's posse. As Penny grows more attached to her new friends and their reckless lifestyle, she pushes Maddie away and rejects her protection. There is not section in the novel told by Penny's perspective.