Since they were seven, Elizabeth and Jessica Wakefield have wanted a little sister. Now that they're twelve, the twins know they're determined to prove it to their parents.
The twins get the chance when neighbors go on vacation and leave their five-year-old daughter with the Wakefields. Chrissy's so cute and sweet, Jessica and Elizabeth think it's going to be easy to take care of her. But from the moment Chrissy arrives, it's clear that she's spoiled. Before long, the twins begin to wish she would just disappear!
When they get their wish and Chrissy does disappear, the twins are faced with their biggest problem yet. They've got to find Chrissy before her parents come back!

In the kitchen, Jessica was bubbling with excitement. "I've got it, Elizabeth!" she whispered loudly.
"Got what?" Elizabeth asked, taking the ice cream from the freezer.
"An idea! A stroke of genius! Look, the Steeles need somebody to watch Chrissy. We need to borrow a little sister or brother to prove to Mom and Dad how much help we'd be if we had a baby in the family. It's perfect!"
Elizabeth stared at Jessica. She wondered if she'd heard right. "Are you suggesting that we keep Chrissy?"
Jessica claped her hands. "Exactly!"
"Well, Chrissy is sweet," Elizabeth agreed as she spooned out some ice cream. "But it would be a lot of work, Jessica. We'd have to take her to school and pick her up and put her to bed every night-"
"But that's why it's so perfect! It's loads of work. And you and I are going to do every bit of it! This is my grandest scheme ever!"
Elizabeth put down the spoon. "Except for one small flaw."
"What's that?" Jessica asked.
"If you don't do your share of taking care of Chrissy," she said bluntly, "I'll end up with double the work!"

Will Jessica become friends with the new girl in school? Jessica and the Secret Star