Young Adult Fiction. Young Adult Literature. HTML: This contemporary teen novel, written by Robin Jones Gunn, portrays a teen who writes her thoughts about God, life, and love. Here's your chance to peek into Christy Miller's diary...with her permission, of course. What's Christy thinking and feeling after she graduates from high school? After college? After she gets married? You'll find out here, on the pages of Christy Miller's Diary, where Christy writes her thoughts about God, life and love. The idea of finding out what Christy wrote in her diary formed the inspiration for Robin, an avid journaler herself, to create Christy Miller's Diary. Robin Jones Gunn has penned dozens of teen novels, including the popular Christy Miller Series, Sierra Jensen Series and Kaatie Weldon Series..