At age 16 Morrissey left her birthplace, The Beaches, a small outport on the west coast of Newfoundland. She lived in various places in Canada before returning to St. John's, where she studied at Memorial University and obtained a Bachelor of Social Work and a diploma in adult education. Morrissey now lives in Halifax, Nova Scotia.
Morrissey has written six national best sellers and prize-winning novels — Kit's Law, Downhill Chance, Sylvanus Now, What They Wanted, The Deception of Livvy Higgs, and The Fortunate Brother — as well as one Gemini-nominated [screenplay]].
Morrissey defended Frank Parker Day's novel Rockbound in Canada Reads 2005. Rockbound eventually won the competition. In the 2007 edition of Canada Reads, an "all-star" competition pitting the five winning advocates from previous years against each other, Morrissey returned to champion Anosh Irani's novel The Song of Kahunsha.