Rattlesnake Rock

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...