The bible tells us the Jesus had brother and sisters. His brothers' names were James, Joseph, Simon and Judas. He also had sisters although their names are not given. This is a very interesting fact, but usually it is not thought about very often. Jesus, the Son of Mary and Son of God, had half siblings. Since Mary's husband, Joseph was not his biological father, the only connection to his brothers and sisters is through Mary. But that is enough to make it interesting. If one thinks about it, there were several people that had the same blood in them as did the Creator of the heavens and the Earth, the One in whom all the fullness of the Godhead dwells.
What does that mean? That means that it is likely that there is some blood relative of Jesus walking around this earth today. That is quite amazing. No. Mary, his mother, was not special of herself other than being the mother of Jesus. She is not sinless as Roman Catholics purport. She is not to be worshipped as Roman Catholics tend to do. She is merely a human like any other. However her blood ran through her first-born Son. That same blood died on a cross to save many from their sins. And it is that blood that runs through the veins of some unknowns alive today.
It is good that we do not know who they are. Just like it is good that we do not have pieces of the true cross or the robe which Jesus wore since we are so apt to make idols of such things. So too we would likely admire and exult some blood-relative of the only Holy one. However, it is very interesting to think about nonetheless.