I found several different things for the same Nancy Hatfield & John F Dunagan. I hope this helps you.
b.12 Jan 1816
married John Franklin Dunagan in Owen Co. IN 12 May 1832
married Charles H Carter 24 April 1843, Clinton Co MO
James Franklin Dunagan
Amanda Jane Dunagan
Willard Edward Dunagan
Thomas Alexander Dunagan
Benjamin Franklin Dunagan
And although her name is similar, she is not the Nancy Hatfield McCoy of the famous feud.