On 4 April 1828 Margaret Oliphant was born in the village of Wallyford, Midlothian, in an old farmhouse with a half-turret enclosing the stairs, and a large low drawing room looking out on Arthur's Seat and Edinburgh beyond. In the following three stories the central character lives in this house. (The first story uses the fictional name of Ailieford for the village.)
Margaret's family had moved away while she was too young to remember the house, but at age 23 she visited it with her mother and took a great liking to it. She tells us in her Autobiography (page 30) that in later years she sometimes thought of living there herself, but ". . . before I could have carried out such an idea, even had it been more real than a fancy, the pretty house was pulled down, and a square, aggressive, and very commonplace new farmhouse built in its place."
It appears from local documentation that the farm's name was Wallyford Farm, which might explain why in the story Wallyford, the house is referred to as if its name is Wallyford too. (But it should not be confused with Wallyford House, a nearby large country house, untenanted and partially in ruins at the time of these stories (1820s - 1830s), and briefly featured in Isabel Dysart.)
Fyi, the village of Wallyford in Midlothian was on the border of East Lothian; and years later when the boundaries were redrawn, became part of the county of East Lothian. This is why some sources incorrectly assign Margaret Oliphant's birthplace to East Lothian.