The McCullys were very good at living as if they were rich.
A line which should tell you nearly everything you need to know about the McCullys. It's the same old mid-century story - a big rambling old house at the unfashionable end of town (which is never the criminal end of town, though), 'only' a few servants, a charming garden, rebellious children with upright hearts, and local roots that extend back a good many years. They would be tiresome except for the humor:
Not truly a horse book, as the majority of the action does not directly involve a horse or pony. But a book about every horsey child's dream - getting a pony under the tree - must be included.
Dorothy Crayder apparently wrote other children's books, but nothing seems horsey
Other seasonal horse books
A Horse For Christmas Morning by Gordon Grand (foxhunting)
The Christmas Horse by Glenn Balch
The Christmas Pony by Sylvia Green
Issie And The Christmas Pony by Stacy Gregg
The Christmas Pony by Wendy Douthwaite (series)
A Horse For Christmas by Joanna Campbell (series)
Starlight Christmas by Bonnie Bryant (series)
Stubby Pringle's Christmas by Jack Schaefer
(a novella really, and about a cowboy, but wonderful Lorence Bjorklund illustrations)
A Miserable, Merry Christmas by Lincoln Steffens (from his autobiography)
(a short story which appears in many anthologies)