Carole Hanson has always wanted a brother or sister. So she should be delighted when her father tells her that thirteen-year-old Marie Dana will be staying with them for two weeks while Mrs. Dana is out of town. But instead of being happy about her "temporary sister", Carole can barely contain her jealousy. Colonel Hanson is making a big fuss over Marie; and Stevie and Lisa are planning a big party for Marie in the hay loft at Pine Hollow.
Will Carole manage to put aside her jealousy before Marie's visit is over? Not until she discovers some common ground in the stables at Pine Hollow.