The Ghost Children — Eve Bunting

When Matt and Abby go to live with Great-Aunt Gerda in Sierra Madre Canyon after their mother dies, Matt is put off at first by the life-size wooden dolls whom Aunt Gerda talks to and calls her “children.” However, when someone vandalizes the dolls and two are stolen, it is Matt, with the help of his new friend, Kristin, who foils the would-be thief and returns the dolls to Aunt Gerda.