Genesis 36:22

The sons of Lotan were Hori and Heman.
Timna was Lotan’s sister.

Lotan’s sons: Hori and Homam. Timna was Lotan’s sister.

Treasury of Scripture Knowledge

And the children of Lotan were Hori and Hemam; and Lotan's sister was Timna.

Timna, a concubine of Esau’s son Eliphaz,
bore Amalek to Eliphaz.
These were the sons of Esau’s wife Adah.