Carole's father's friends' daughters going to be staying with them for a while! Carole should be over the moon-I mean, she's always wanted a sister! But soon she is suffering from acute sibling rivalry! Of course, when Stevie gets involved, everything takes a crazy twist- don't even ask about the square dancing, and the plan to throw Carole's "substitue sister" out of the hayloft at Pine Hollow. Will everything go back to normal for the Saddle Club? Will Carole recover? Will Stevie's harebrained scheme work?