Baby Betsy is a large china baby-doll. She is the daughter of Mama and Papa Doll, as well as younger sister of Annabelle, Bobby, and Tilly May. She is also niece of Auntie Sarah and Uncle Doll. She is about the size of her parents. She is thought to be about 1 or 2 years old, because she is old enough to understand what she must do to remain a living doll, but cannot speak or walk as far as we know.
She was originally made to be part of a larger doll set, but was accidentally included in the package that was sent to the Cox family. The Coxs puzzled about her when they received to package, but kept her, to the great relief of the Doll family. She is adopted, in a sense, but just as much a memember of the family as all the others.