These are the names of Esau's sons; Eliphaz,Eliphaz... And Timna was concubine to Eliphaz.... Genesis 36:10-12
The sons of Esau; Eliphaz.....The sons of Eliphaz ... Timnah.... 1 Chronicles 1:35-36
Both of these verses come from lists of Esau's descendants, so it seems likely Timnah that refers to the same person.
Credit: All That's Wrong with the Bible: Contradictions, Absurdities, and More by Johan David Conner