She is best remembered for her timeless devotional classic, Streams in the Desert (1925), which she compiled during the six years she devotedly nursed her ailing husband. Drawing from sermons, poetry, and the writings of various Christian authors, the book offers daily readings of comfort and hope. It has sold millions of copies worldwide and has been translated into numerous languages, remaining one of the most cherished devotional works in Christian literature.
Her other notable works include Springs in the Valley (1939), another beloved devotional collection; Missionary Warrior (1928), a biography of her husband; and Mountain Trailways, a devotional written for young readers. Following her husband's death in 1924, Cowman continued writing and serving the mission society until her death in Los Angeles in 1960. Her writings continue to inspire generations of readers with enduring messages of faith, perseverance, and divine consolation.