Born in Grande Prairie, Alberta, Leslie was educated at the University of Lethbridge, from which she received Bachelor of Arts and Bachelor of Education degrees.
Greentree's first book of poetry, guys named Bill came out in 2002 was quickly followed in 2003 by go-go dancing for Elvis.
In 2006, Greentree published her first collection of short stories, entitled A Minor Planet for You and won the Alberta Literary Awards Howard O'Hagan prize for best book of short fiction (2007).
Oral Fixations, Greentree's first play, co-written with Blaine Newton, received its world premiere in October 2014.
It was produced by Ignition Theatre in Red Deer, Alberta.