JK Rowling has written a personal letter to Cassidy Stay, the girl who survived a shooting in which her family was killed. Cassidy found strength in Rowling's words and quoted a line from Harry Potter's Dumbledore at a family memorial held days after the shooting. The teenager said: "In The Prisoner of Azkaban, Dumbledore says, 'Happiness can be found even in the darkest times if one only remembers to turn on the light'. "I know that my mom, dad, Bryan, Emily, Becca, and Zach are in a much better place and that I'll be able to see them again one day. Stay strong". http://www.youtube.com/watch?v=ppKh6HHO9oM Fifteen-year-old Cassidy, the oldest of five children, lost her parents and four siblings in the horrific attack. The teenager was grazed by a bullet and survived the attack by playing dead. An online campaign resulted in JK Rowling sending Cassidy a note written in purple ink, a wand, an acceptance letter to Hogwarts, a list of school supplies and a signed book. JK Rowling sent Cassidy a letter "We can confirm that JK Rowling was in touch with Cassidy Stay, however, the contents of the letter remain private," a spokesperson for Rowling told The Telegraph. Asked about whether the two would meet, she said: "We wouldn't comment on that but [Cassidy's] is a remarkable story." Ronald Lee Haskin, the brother-in-law of Cassidy's mother, has been charged with capital murder over the six deaths.