Looking for a book about a teenage girl who lives alone with her father. Her brother was killed when he fell off their horse and she refuses to touch the horse anymore, only going into the barn to feed the horse. She lives in the mountains somewhere, they still have a communal phone line, which she uses to order clothes while her father is away on his sales route.
There is a new family in town, maybe the new mayor or teacher, someone important, there is a parade or celebration of some sort where she sees the young boy be given a piece of candy by an elderly woman that the town thinks is kind of crazy.
Shortly after that the boy is kidnapped. There is an abandoned homestead behind her land and a couple moves in. The man does work for her. She starts to wonder about the couple, goes to investigate and finds the young boy. She then devises a way to get the boy back. She uses the horse because she has no way to get into town without the horse. Describes her home as a shotgun house.