Rattlesnake Rock — Angela Dorsey

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