In addition to her career in journalism, Cumming has written well-received books on self-portraits in art and the discovery of a lost portrait by Diego Velázquez in 1845.

The Vanishing Man was a New York Times bestseller[1] and won the James Tait Black Memorial Prize in 2016.

She initially studied literature, came to London in her early twenties, and worked there in publishing in the 1980s, though she found her 'sense of life' came 'through streams of pictures' rather than sentences.

[8] Her work on the discovery of a lost Diego Velázquez portrait by John Snare in 1845, The Vanishing Man: In Pursuit of Velázquez (2016), was described by Honor Clerk in The Spectator as "a study in obsession, a paean of praise to an artist of genius, a detective story and, for the author, an exorcism of grief".

[10] Jonathan Beckman in The Times, however, felt that the book was "breathless" and that its source materials (or lack thereof) didn't completely support the weight that Cumming placed on them.