Wiggin began her literary career with The Birds' Christmas Carol (1887), a heartwarming Christmas tale that achieved great popularity. Her most famous novel, Rebecca of Sunnybrook Farm (1903), portrays an imaginative young girl growing up with her aunts in rural Maine and remains a cherished work of American children's literature. Other notable works include Timothy's Quest (1890), Polly Oliver's Problem (1893), Penelope's English Experiences (1893), The Old Peabody Pew (1907), and Mother Carey's Chickens (1911). She also co-authored several collections of fairy tales with her sister, Nora A. Smith.
Blending humor, warmth, and moral sensibility, Wiggin's writing vividly captured rural New England life and the inner world of children, securing her a lasting place in American literary history.