Who is Sam Atwell in the novel, The Yonahlossee Riding Camp For Girls?

Sam is Thea's twin brother. He is a gentle and calm lover of nature. Alongside Thea, he spent his childhood exploring the outdoors. When Thea begins her romantic relationship with Georgie, Sam is suspicious. Gradually, a wall builds between Sam and Thea that changes their relationship to be not as close as it once was. Sam attacks Georgie and leaves him with brain damage. Following this fight, Thea goes to Yonahlossee while Sam remains at home. He grows up during this period and becomes a more closed-off, sullen person who believes he deserves blame and punishment for his actions. After the events of the novel, Sam marries and has children, but remains in Florida for the rest of his life.