I don't know if this is any connection to the line you're interested in, but Euphemia (Davis) Templeton (born ca 1786 Rowan Co NC) is living in Black Twp., Posey Co, Indiana at the 1850 census (household of William and Martha Todd; Martha is born in TN about 1813 -- her daughter?). There is also a Samuel M. Templeton, born NC about 1784, with wife Sarah and children in the same township. (He and family are also in the 1840 census of that township.)
In the 1860 census she's in Smith Co TN living with her brother Benjamin Merrill Davis 1791-1875 my gr gr gr grandfather.
I suspect that she lived in Lincoln Co TN some time before that, and her unknown husband may have associations with Iredell Co NC near Rowan.