Kmg - We stayed in a brilliant place just outside Torrington, Nth Devon, in June. Its a non-working farm, with 5 converted cottages, set around an enclosed courtyard (great for kids).
The place is run for children, with chickens, ducks, goose, goats, donkeys, ponies, Bella the cow, sheep, rabbits, ginea pigs, etc etc. There is a laundry room, and the couple who run it are great, and encouraged our 21mth old to feed everything, twice a day!
They do tractor rides, there is a big field to play and run around in, with play equipment. A heated indoor pool, games room with lots of toys, b-b-q, wooden playhouse with toys.
Torrington is a quiet market town, around 12 miles inland from Bideford and Westward Ho.
Oh, also, the cottages are equipped for children too. They all have microwaves, stair gates, proper cots, and highchairs. The couple have two daughters who babysit too! What more could I want? We have booked again for next year, and are planning a long weekend break before winter.
The place is called Hill Farm, run by Bob and Mary Vickery. Hope this is something like what you are after.