Her father, Harold Pullein-Thompson, had the Military Cross and her mother, Joanna Cannan an author credited with starting the idea of pony books in 1936.

[4] He had been a teacher but he then sold fridges and had a game company,[5] but it has her mother who made more money writing pony books on the kitchen table.

[5] In time they would describe their country childhood in their joint auto biography Fair Girls and Grey Horses (2014).

[2] The girls had an unusual education as distinct from their brother who went to Eton College; their mother taught them at home.

Christine went to start work in Virginia,[2] but Diana was denied entry to the USA in 1952, as the medical revealed that she had tuberculosis.

Christine returned to be with her[2] and Diana was sent to recover in Switzerland courtesy of the country's new National Health Service.

She wrote several book series including one about a ghost horse and another about a dog named Jessie.

[1] Note: The Impossible Horse has been published under the name of Christine Keir, which may have been a pseudonym, as it is the same story.