I guess the answer would be that there aren’t genealogies that go that far back. Who there were doesn’t really matter b/c they weren’t a part of Jesus’ ministry.
I’m trying to come up with more answers they might give.
You can’t use that argument.
Jesus genealogy in scripture goes back to Adam.
[Lk 3:23-38]
23 Now Jesus himself was about thirty years old when he began his ministry. He was the son, so it was thought, of Joseph, the son of Heli, 24 the son of Matthat, the son of Levi, the son of Melki, the son of Jannai, the son of Joseph, 25 the son of Mattathias, the son of Amos, the son of Nahum, the son of Esli, the son of Naggai, 26 the son of Maath, the son of Mattathias, the son of Semein, the son of Josech, the son of Joda, 27 the son of Joanan, the son of Rhesa, the son of Zerubbabel, the son of Shealtiel, the son of Neri, 28 the son of Melki, the son of Addi, the son of Cosam, the son of Elmadam, the son of Er, 29 the son of Joshua, the son of Eliezer, the son of Jorim, the son of Matthat, the son of Levi, 30 the son of Simeon, the son of Judah, the son of Joseph, the son of Jonam, the son of Eliakim, 31 the son of Melea, the son of Menna, the son of Mattatha, the son of Nathan, the son of David, 32 the son of Jesse, the son of Obed, the son of Boaz, the son of Salmon, the son of Nahshon, 33 the son of Amminadab, the son of Ram, the son of Hezron, the son of Perez, the son of Judah, 34 the son of Jacob, the son of Isaac, the son of Abraham, the son of Terah, the son of Nahor, 35 the son of Serug, the son of Reu, the son of Peleg, the son of Eber, the son of Shelah, 36 the son of Cainan, the son of Arphaxad, the son of Shem, the son of Noah, the son of Lamech, 37 the son of Methuselah, the son of Enoch, the son of Jared, the son of Mahalalel, the son of Kenan, 38 the son of Enosh, the son of Seth, the son of Adam, the son of God.
Obviously Jews kept excellent records of genealogies. So if Mary had other children, given this detailed lineage of her son Jesus, it wouldn’t be hard to trace her other children if she had them.