Hi
I too have the same info of Hannah Blight marrying James Jeffery in Illogan, in 1840. They did have more children than Jane b 1841, Eliza, Hannah, James, Edward, Stephen, Robert. These are names I have from the census records, so there maybe more in between.
James seems to die 1851-1861, and after 1871 there is grandchildren living with Hannah.
I am from Janes line, who married a James Harris Andrew, and they went to Australia, and then on to New Zealand.
Have quite a few "Jeffery" names also if you are interested.
Regards Gail