Basemath Ishmael's daughter, sister of Nebaioth.

‘Esau took his wives of the daughters of Canaan; Adah the daughter of Elon the Hittite, and Oholibamah the daughter of Anah, the daughter of Zibeon the Hivite, and Basemath Ishmael’s daughter, sister of Nebaioth.’ Genesis 36, 2-3