I am confused about this information. Are you thinking these are Martha's parents? I think there is something with this though. Martha's daughter and my 2nd great grandmother was named Mary Temperance. I don't see Martha's name on there though. She was already married by the 1850 census, but she could be one of the kids on the 1840 census. Is the father Samuel Bishop in both, married to Temperance?
So Temperance Lindsay became Temperance Northington and finally Temperance Bishop. Her first name was Mary? It has to be it!