Notable for her works of children's and young adult literature, she received a Golden Kite Award for her 1976 work One More Flight and an Edgar Award for her 1992 children's mystery novel Coffin on a Case! Over the course of her career, she published more than 250 books.
Before beginning her literary career, she studied at Methodist College and Queen's University (both in Northern Ireland) and took writing courses at Pasadena City College (in California, U.S.A.). She published her first story, "The Two Giants," in 1971.
She taught creative writing at the University of California, Los Angeles.
Born to Mary Canning Bolton and Sloan Edmund Bolton in Maghera, Northern Ireland, she later lived in Scotland and the United States with her husband, Edward Davison Bunting, and her children Glenn, Sloan, and Christine.
She and Martin Waddell are both well known Northern Irish-born children's authors.