Miller was born in Vancouver, Canada and came to Australia at the age of two. After graduating from the Sydney University of Technology she moved to England for three years before moving back to Australia. Along with being a novelist she has written and directed plays for her local theatre group.
In 2005 Miller's first novel was released entitled The Innocent Mage. This was the first novel in the Kingmaker, Kingbreaker series and was followed shortly after by Innocence Lost. The Innocent Mage was widely acclaimed on it release in Australia and was a finalist in the 2005 Aurealis Awards fantasy division. Since then she has written several other novels, Empress of Mijak and The Riven Kingdom were honoured by the James Tiptree, Jr. Awards and has written two novels for Fandemonium's Stargate SG-1 series.
Miller also writes under the pseudonym K. E. Mills, releasing the first novel in the Rogue Agent series, The Accidental Sorcerer under this pen name.