What Girls Are Made Of (Fiction — Young Adult) by Elana K. Arnold

When Nina Faye was fourteen, her mother told her there was no such thing as unconditional love. Nina believed her. Now she'll do anything for the boy she loves, to prove she's worthy of him. But when he breaks up with her, Nina is lost. What is she if not a girlfriend? What is she made of? Broken-hearted, Nina tries to figure out what the conditions of love are.