Bittersweet Farm 3: Wingspread (Volume 3)

"Surprise!" Greer's mother says with her unannounced arrival. What Victoria Swope is doing in town is puzzling but they quickly learn the reason and no one is pleased.
When Greer demands to be home-schooled with Talia, the lessons at Bittersweet Farm aren't restricted to dressage, cross-country and show jumping. If the half-sisters can't get along, one of them will be sent abroad to finish high school. Unable to bear leaving the farm's trainer, Lockie Malone, or her horse, CB, Talia grits her teeth and tries to move forward.
It's soon obvious that everyone at the farm faces changes and challenges. Solving them is difficult and maybe impossible.