Kirsten's excited about the changes spring is bringing to the Larsons’ farm—including a big barn and a tiny baby. But changes bring new worries and more work, too. First Kirsten is afraid for Mama’s health. Then caring for a baby seems to mean nothing but chores. Kirsten has to miss school to help at home, and she can’t help with the surprise she and her friends are planning for their teacher. Will her friends forget all about her? But Kirsten’s hard work is rewarded with a day of fun—and a special birthday surprise.