Mary Jane might become Nancy Jane, Obadiah might become Oliver, etc. They guessed at the ages. Sometimes the parents were in the fields and the kids gave the information. This is usually obvious. The kids names and ages are correct, the mother s age too young and the father s age too old.
Kids know each other s ages, and usually think their mother is young and their father is old.
She had five, all grown and married. Children often didn t like their names, so as soon as they were old enough, they changed them. I have several named Susannah. All of them were Susannah on the census as children, but on their marriage records and later census records, they were Susan . One girl was Rosanna in the family Bible.