Catherine was born in Brisbane, Queensland. She grew up in Papua New Guinea, where her father worked as a patrol officer. She went to high school in Sydney. In 2006, her alma mater, Ku-ring-gai High School, named its library after her. From 1982 to 1986, Catherine studied at the University of Sydney, graduating with an honours degree in medieval history. She then worked on Westpac Banking Corporation’s staff magazine for approximately seven years. In 1992 she married Peter Dockrill, a Canadian journalist; in 1993 she and her husband left Australia for a brief spell in Nova Scotia, where she began to write full time. They returned to Australia in 1994, and Catherine gave birth to her daughter Hannah in 1997. Since 1998, she and her family have been living in Leura, New South Wales.

Children's books

• The Secret of Hermitage Isle (1997)
• The Horrible Holiday (1998)
• The Stinking Great Lie (1999)
• You'll Wake the Baby, illustrated by Andrew McLean (2000)
• Daryl's Dinner (2002)
• Katie and Cleo Move In, illustrated by Andrew McLean (2007)

Allie's Ghost Hunters series

• Eglantine (2002)
• Eustace (2003)
• Eloise (2004)
• Elysium (2007)

Young Adult books

• This Way Out (1991)
• The Future Trap (1993)
• Witch Bank (1995)
• Eye to Eye (1997)
• Piggy in the Middle (1998)
• What's Hector McKerrow Doing These Days? (also known as To Die For in the UK (2000)
• The Rapture (2001)
• Living Hell (2007)
• Babylonne (2008) (also a companion to the Pagan Chronicles)
• The Reformed Vampire Support Group (2009)
• The Abused Werewolf Rescue Group (2011) (also a companion to The Reformed Vampire Support Group)

Pagan Chronicles

• Pagan's Crusade (1992)
• Pagan in Exile (1994)
• Pagan's Vows (1995)
• Pagan's Scribe (1995)
• Pagan's Daughter (also known as Babylonne (2007)

Evil Genius series

• Evil Genius (2005) (red cover)
• Genius Squad (2008) (green cover)
• Genius Wars (2009) (black cover)

Adult books

• An Evening with the Messiah (1996)
• Little White Secrets (1997)
• The Inquisitor (1999)
• The Notary (2000)
• Bella Vista (2001)
• The Gentlemen's Garden (2002)
• Spinning Around (2004)
• The Road (2004)
• The Secret Familiar (2006)
• Deck Free E-novel (2007)
• The Dark Mountain (2008)