Keeker and the Not-So-Sleepy Hollow — Hadley Higginson

Keeker and Plum are excited to visit family this summer, until they find out that a local town is haunted -- by a headless horseman!
 
When Keeker and Plum take a road trip to upstate New York, Keeker is sure it will be the best family vacation yet. (Plum, on the other hand, is not convinced!) Keeker is excited to splash in the neighborhood pond and ride ponies in the country with her cousins. What she doesn't know is that the nearby town of Sleepy Hollow holds a mystery that will make this a very ghostly getaway!
 
Praise for the Sneaky Pony series
 
“These books are terrific first chapter books for young readers, quirky and compelling; the line drawings of the girl and her horse are simple but beguiling.” -- Entertainment Weekly
 
“I don't bandy the word ‘delightful' around lightly, but the retro flavor with contemporary appeal wins the Delightful Derby, and I am so happy to be able to recommend a romp down a reading trail that little girls will really enjoy.” -- PlanetEsme