There was some digging into history on her part.
It was true that Tom was much easier to care for than the average baby. He was able to adapt to new situations far more quickly than other infants his age and only screamed when he was hungry. However, Sally was everything from fine. She lived in continual fear that the bad luck associated with his birth day would eventually harm or kill her beautiful newborn. She was so fed up with stress that she started to investigate the issue.