Zoe Sugg is a multi-hyphenate businesswoman, content creator and the bestselling author of the Girl Online series. In 2009, she started her blog and social media channels under the name "Zoella" and took the online world by storm. She has amassed 25 million followers across her YouTube and Instagram channels, and regularly uses her platform to address important subjects like mental health, cyber-bullying and women's health.

Amy McCulloch is a Chinese-White author, raised in Canada and based in London, England. Amy has been editorial director for Penguin Random House Children's, where she published Zoe's #1 international bestselling series Girl Online, and has written for YA and middle-grade readers in her series The Oathbreaker's Shadow, The Potion Diaries and Jinxed. When she's not writing, she can normally be found on top of a mountain.