I found several different things for the same Nancy Hatfield & John F Dunagan. I hope this helps you.
Nancy Hatfield
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
Children:
James Franklin Dunagan
b 1833
Amanda Jane Dunagan
b 1834
Willard Edward Dunagan
b 1836
Thomas Alexander Dunagan
b 1839
Benjamin Franklin Dunagan
b 1841
And although her name is similar, she is not the Nancy Hatfield McCoy of the famous feud.