Jane Macklem was born October 27, 1884, in Quincy, Michigan. In 1907 she married attorney James Murfin, and retained his surname when the marriage ended fewer than five years later.
Murfin began her career with the play Lilac Time, which she co-wrote with actress Jane Cowl. The Broadway production opened February 6, 1917, and ran for 176 performances. Later that year the two women began collaborating, often under pseudonym Allan Langdon Martin, on a series of revivals of World War I melodramas. The pair later collaborated on Daybreak, followed by Information Please (1918) and Smilin' Through (1919).
In Hollywood, Murfin became a leading screenwriter, writing many romantic comedies and dramas by herself or in collaboration.
In 1920, director Laurence Trimble persuaded Murfin to purchase a German Shepherd dog—Strongheart—that became the first major canine film star. Strongheart starred in four films that Trimble directed from Murfin's screenplays: The Silent Call (1921), Brawn of the North (1922), The Love Master (1924) and White Fang (1925).
Murfin is credited with directing one film, Flapper Wives (1924), before the dissolution of her partnership with Trimble. Film historian Kevin Brownlow described this partnership as both professional and personal; although some sources describe Trimble and Murfin as a husband-and-wife filmmaking team, no marriage has been substantiated.