These are the names of the sons of Ishmael by their generations: Ishmael's first son was Nebaioth; then Kedar and Adbeel and Mibsam

So Esau went to Ishmael and took Mahalath, the daughter of Abraham's son Ishmael, the sister of Nebaioth, to be his wife in addition to the wives he had.

And Basemath, Ishmael's daughter, the sister of Nebaioth.