Dawn and the Impossible Three — Ann M. Martin

Dawn's the newest member of the Baby-sitters Club and everybody's glad -- except Kristy. Kristy thinks things were better without Dawn around. That's why Dawn's eager to take on a big baby-sitting job: It's her chance to show Kristy what she's made of.

What a mistake! Taking care of the three Barrett kids is too much for any baby-sifter. The house is in chaos, the kids are impossible, and Mrs. Barrett never does any of the things she promises. Dawn's got more trouble than she bargained for. But she's not going to give up until all four Barrens are under control and she's friends with Kristy. Or whichever comes first!