She worked as a translator of Greek texts for Robert Graves and she became a life-long muse and collaborator with her prolific writer husband Martin Seymour-Smith.
Her parents were Hilda St Hilary Edith Everard (born Mayne) and her husband Lionel Richard Gethin de Glanville.
When Robert Graves published The Greek Myths in two volumes in 1955 he had based his work on the translations by Janet Seymour-Smith.
[2] Robert Graves who was their employer and an old school friend of Martin's was a witness at their wedding at Mallorca's British Consulate in 1952.
[2] When Robert Nye published Mrs. Shakespeare: The Complete Works in 2000 he devoted the book to Martin and Janet Seymour-Smith.