Monica and the Worst Horse Ever — Diana G. Gallagher

Monica and her Rock River Stables friends are headed on a trail ride for the weekend. But from the start, things go wrong: Monica's horse can't go, so she has to ride an old pony. The snobby horse owners are making fun of everyone, as usual, and bossing Rory around. And worst of all, a really annoying kid from another town has started hanging around Monica and Chloe. Will the trail ride be able to find its way back on track?