Books in the Horse Guardian series

Rosa is faced with a terrible choice. Senor Garcia, the owner of the Mexican ranch where she and her family live, has offered her a dream job and a mustang colt of her own. If she accepts his offer, five of the twelve recently captured mustangs get to live, her parents get to keep their jobs, and her friend gets a new assistant: her.Almost everyone will be a winner. Almost. Seven unwanted mustangs will be sent to slaughter.Can Rosa let that happen? But what choice does she have? There's no way she can save the mustangs...

Sophie has lost count of all the foster homes she's lived in. Finally, at Joel and Kalene's ranch, she feels at home. When she unwittingly puts their most valuable mare, Aria, in danger, she is terrified she'll be sent away and conceals her mistake - and Aria - letting her foster parents believe the mare was stolen.Then Sophie is hit by a car. She knows she must go to Aria as soon as she can, though she's not sure how she's going to carry hay with a broken arm.But feeling hungry is not Aria's biggest problem, for a terrible evil has found her and knows she is alone.