There's no assuming. You're either a physical child or adopted. The prophecies require physical descent. From the male loins and male seed.The Jew's assumed that Joseph was Jesus' physical father and His tribe would still be Judah fulfilling the prophecy anyway.
It doesn't help you. Mary wasn't a king, queen, that could pass on anything.I gave you the link that tied in Mary's part and the importance of the woman's lineage, didn't you read it?