Isabel Ostrander (1883–1924)

Isabel Ostrander was born in New York City to Thomas E Ostrander and his wife Harriet Elizabeth Bradbrook. She was descended from 17th-century settlers in Kingston, NY. She became a prolific mystery writer who used, besides her real name, the pseudonyms Robert Orr Chipperfield, David Fox, and Douglas Grant. By the 1920s, Ostrander was famous enough that Agatha Christie parodied her in the Tommy and Tuppence short story collection, Partners in Crime. She is also credited on IMDB.com as the screenwriter of six short early films.

Robert Orr Chipperfield was one of many pseudonyms used by American mystery writer Isabel Egenton Ostrander (1883-1924) She also wrote as David Fox and Douglas Grant. Although she may have written with Christopher B. Booth, they were not the same person.