Because laws are made for most people, not special cases.
Jesus was BAPTIZED—with John’s baptism of repentance. Do you conclude from this fact that Jesus was a sinner?
Admit it Arthur, the texts are solidly against Mary being sinless.
Matthew 3:15 Douay-Rheims Bible
And Jesus answering, said to him: Suffer it to be so now. For so it becometh us to fulfill all justice. Then he suffered him.
Just WHERE is baptism even MENTIONED in the LAW?