Maria Merryweather is the main character in the novel "The Little White Horse" by Elizabeth Goudge. She is a young girl who moves to the countryside after the death of her father. Maria is kind-hearted, curious, and brave, often finding herself in magical adventures. Throughout the story, Maria discovers her family's history and the enchanting world around her. She befriends various characters, including Robin, a loyal friend, and Sir Benjamin, a wise figure. Maria's journey is one of self-discovery, love, and the importance of home and family.