All your names sound familiar but they aren't connecting right. It's possible that I don't have something right too though.
I have a Murdoch Martin being born to Norman Martin and Anna Morrison. Norman has a brother named Daniel who I have as being born around 1794. Norman's parents were John Martin and Mary Susan Polly McDuffie. Parent's of Polly McDuffie are John McDuffie and Flora McDonald.
I also have John and Flora McDonald McDuffie with a child named Norman who had a child named Flora and a child named Murdock. I have no other info on these two except for their names. Could this be the Flora McDuffie you are asking about? If so, please let me know so that I can fill in the rest of their info. I also think they may have been born in Greene County and could be helpful in figuring out some other info I'm looking for.
This family gets really confusing because all of the same names........