Emma Redington Lee was born April 5, 1874. She studied at Cooper Union and Pratt Institute. Her husband was Harry Thayer, an artist.

Thayer wrote 60 mystery novels about well-mannered private investigator Peter Clancy and his valet, Wiggar. She wrote her first novel, The Mystery of the Thirteenth Floor in 1919. Her last novel, Dusty Death, was published in 1966, when she was 92.

Thayer and her husband opened a publisher's art service, which specialized in book jacket art work.

On May 11, 1958, Thayer was a contestant on What's My Line?