Have you looked at the wills from Oneida County? There is a will of William Peacock drawn on 11/20/1834 executed 12/22/1834 which names his wife Mary, son William, daughter Julia, niece Ellen Gysson (wife of Benjamin) and (no relationship given) George Peacock, Mary Peacock and Ann Peacock- all minors.
wife Mary got use of land in Connecticut for the remainder of her life and children William and Julia got the land after that. Niece Ellen got $150. and George, Mary, Ann got the residue of his property (most likely what he owned in Oneida county). Guardianship of this property until George, Mary, and Ann reached adulthood was given to his son-in-law Benjamin Gysson.