All four of Terah's children are direct ancestors of Jesus Christ. If you refer to the diagram to the right you can see how. The dotted lines denote marriage.
Terah's kids are Sarai (renamed Sarah by God), Abram (renamed Abraham by God), Nahor, and Haran.
First, notice Sarai, Abram's wife, is actually Abram's half-sister as Abram himself says in Genesis 20:12. She marries Abram and together they have Isaac, who fathers Jacob, who father's Judah, which leads to Jesus Christ (Matthew 1:1-16; Luke 3:23-34; Hebrews 7:14).
Second, of course, Abram is Jesus' direct ancestor in the same manner as Sarai, his wife. God identifies Himself as the "the God of Abraham, the God of Isaac, and the God of Jacob" (Exodus 3:6).
Third, Haran, Abram's and Sarai's brother, has a daughter named Milcah (Genesis 11:29). She is, therefore, Sarai's, Abram's, and Nahor's niece. She contributes to Jesus' ancestry by marrying her uncle Nahor. They have a son named Bethuel (Genesis 22:20-21). Bethuel father's Rebekah (Genesis 22:22), who marries Isaac, both her first cousin once-removed (through Bethuel and Nahor), and her first cousin twice-removed (through Bethuel, Milcah, and Haran). Rebekah and Isaac have Jacob, who then fathers Judah, who, again, leads to Jesus Christ.
Fourth, as already mentioned, Nahor marries his niece, Milcah, and this leads directly to Christ as just outlined above.
But there is another link as you can see in the above diagram, and that is that Bethuel also has a son named Laban (Genesis 24:29). Laban has two daughters, Rachel and Leah (Genesis 29:16). Both of them marry Jacob, their first cousin. And, it is through both Leah and Jacob that Judah is born, which, again, leads to Jesus Christ.
This is how Sarai, Abram, Nahor, and Haran (all siblings) all are direct ancestors of Jesus Christ.
And you thought your family tree was weird.
