Rosemary Anne Sisson

Born in London in 1923. Prolific British scriptwriter, playwright and author, perhaps best known as one of the writers of the cult TV show Upstairs, Downstairs.

She seems to have had an interest in ponies with several of her scripts featuring horses, including episodes of the Follyfoot TV show, and both a film and TV adaptation of  the James Aldridge book A Sporting Proposition (filmed as Ride a Wild Pony), as well as a 1970s TV drama adapted from Horse in the House by William Corbin. To find out more about these please visit the appropriate author's pages, or Rosemary's filmography link.

Rosemary also wrote the script for the Disney film about pit ponies, Escape From the Dark, which she then adapted into a novel.

Her novels are mainly historical, and I think the adaptation of the Disney film was her only pony related one. She did write a play called The Dark Horse, but I think this is a general historical story and nothing to do with horses.

ESCAPE FROM THE DARK
aka THE LITTLEST HORSE THIEVES
(STAR PB 1976)
ILLUSTRATED WITH PHOTOGRAPHS
Reprinted in the USA  by Pocket Books in 1977 as THE LITTLEST HORSE THIEVES
SUMMARY: Novelisation of the author's own screenplay for the Walt Disney film of the same name (in the USA it was however known as The Littlest Horse Thieves), illustrated with photo stills from the film. 
A historical pony story. Dave and Tommy spend all their time down the mine helping to look after the pit ponies they love. But when new manager Mr. Sandman takes over, he decides to mechanise the mine and get rid of the ponies. Forming a surprising alliance with Mr. Sandman's young daughter, the children conspire to rescue the ponies.
PONYMAD RATING: 3-4 HORSESHOES

Collectors info:
Paperback original. No hardback editions as far as I know. Quite easy to find in both the UK and USA version.