Endicott was born Golden, British Columbia in 1958, grew up in Halifax and Yarmouth, Nova Scotia, and Toronto, Ontario. She worked as an actor before moving to London, England, where she began to write fiction. Returning to Canada in 1984, she went west to Saskatoon and worked in theatre as a director and dramaturge. She was for many years the dramaturge of the Saskatchewan Playwrights Centre. In 1992 she went farther west with husband Peter Ormshaw to Mayerthorpe, Alberta, on his first posting with the RCMP; they have since lived in Cochrane and Edmonton, and have two children: Will (1993) and Rachel (1996). They presently (2010) live in Edmonton, Alberta.

Endicott was an actor and director for many years before beginning a second career as a writer of fiction. When asked why she switched, she explained:

Being an actor isn't an easy life. The work is so ephemeral... I write novels instead of plays because I like the intimate link of the silent writer and the silent reader.

Endicott’s first short story appeared in Grain in 1985. Her stories have been anthologized in Coming Attractions and short-listed for the 1993 Journey Prize. Her first novel, Open Arms (2001), was a finalist for the Amazon.ca/Books in Canada First Novel Award and was broadcast on CBC Radio's Between the Covers in 2003. Her long poem about the Mayerthorpe incident, "The Policeman's Wife, Some Letters", was short-listed for the CBC Literary Awards in 2006.