Certainly one to ponder.The responses should be interesting.
Then from Jesus’ words biological relationships were not of great importance compared to the spiritual. As John the baptizer had earlier said, God was able to raise children to Abraham from the stones.
That would explain why Jesus chose the apostle John to care for Mary, John was a more reliable and spiritually trustworthy man than even Jesus’ half-brothers.
I understand what you are saying, but ponder this...Scripture with Scripture:
Joh 7:2 Now the Jews' feast of tabernacles was at hand.
Joh 7:3 His brethren therefore said unto him, Depart hence, and go into Judaea, that thy disciples also may see the works that thou doest.
These appear to be the 12 who were traveling with Jesus...Spiritual brethren...
Joh 7:4 For there is no man that doeth any thing in secret, and he himself seeketh to be known openly. If thou do these things, shew thyself to the world.
Joh 7:5 For neither did his brethren believe in him.
THESE brethren are NOT spiritual brothers...They are blood brothers...
Mar 3:20 And the multitude cometh together again, so that they could not so much as eat bread.
Mar 3:21 And when his friends heard of it, they went out to lay hold on him: for they said, He is beside himself.
The friends and family of Jesus did not believe he was the Messiah, at this point in time...