Happy's Big Plan (Big Apple Barn Series #2) by Kristin Earhart, John Steven Gurney
When Happy Go Lucky, a young quarter pony, is moved from his home to the stables at Big Apple Barn, endless adventures await him!
Happy Go Lucky is quickly learning his way around Big Apple Barn. He's even making new friends like Roscoe, the barn mouse, and Ivy, the trainer's youngest daughter. There's so much to explore!
But Happy soon discovers that working as a school pony won't be easy. Every rider is different, and Happy isn't sure if he likes that. And not all of the animals at Big Apple Barn are very friendly. . . .