She was born in Australia in 1986 and plans to stay alive for as long as possible. She went to Radford College and achieved a Bachelor's Degree in Communications at the University of Canberra, where she returned to obtain a Master of Information Studies in 2012. She now holds down a "real" job as an archivist.

Katie published her first work, The Land of Bad Fantasy, through Scholastic when she was just 18, and went on to publish The Dark Griffin in Australia and New Zealand five years later. The Griffin's Flight and The Griffin's War followed in the same year, and were released in America and Canada in 2011. The Shadow's Heir, The Shadowed Throne and The Shadow's Heart have now joined them in both Australia and the US. Katie collects movie soundtracks and keeps pet rats, and isn't quite as angst-ridden as her books might suggest. She enjoys making (often weird) cuddly toys as a hobby, and sells them privately at conventions. She can now be found on Facebook and Twitter, despite years of vowing never to appear on either. Her achievements so far include being named Young Distinguished Alumni of the Year from the University of Canberra in 2011, winning the Critic's Award that same year, and being shortlisted for the Aurealis Awards in 2009 for The Dark Griffin.