My Little Hubby

In the novel there is a curse cast by a witch in the south, and the man it was put on spends the daylight hours in the body of a small child and comes back to his adult body at night. Willa Shone prays at her great-grandmother's grave for a perfect husband and wakes up inside that novel, in the body of its villainess, a woman written to mistreat the adopted son of the male lead. Willa is good to the boy instead. She meets a small child she does not recognize as Howard Quelch and plays with him for her own amusement. A misunderstanding puts the two of them in the same bed. The novel's original heroine works on the boy until he starts behaving badly, then accuses Willa of having administered the poison. Howard is cold to Willa in front of other people and helps her several times without letting on. When the accusation is put to her, he turns up and lays out what happened. The curse works its way out of him while the two of them are still testing each other, and they take on the person behind the scheme and put a household back together.