Oh dear, sorry! I have obviously not made this clear

Should have put 1st generation, 2nd generation etc.
Robert Biggar & Isabella McWhir's 5th child:
John Biggar (1781-1858)
John Biggar (1813-1884) - first child of John Biggar above (1781-1858)
Robert Biggar (1855-1887) - last child of John Biggar, above (1813-1884)
John Biggar, my grandfather (1884-1946) only son of Robert Biggar (1955-1887)
Evelyn Biggar, my mother (1912-1998)
It would help if they were not all called either John or Robert!
Hope that is clearer now. I was trying for shorthand but obviously not successful.