Jesus didn't leave Mary in the care of her other son's because at the point that he died; none of them were believers. Though James (and later Jude) did become believers; as Paul makes mention of James in
Galatians 1:19: "... James, the Lord's brother."
We also have in Scripture:
Jude, the servant of Jesus Christ, and brother of James, to them that are sanctified by God the Father,and preserved in Jesus Christ,
and called: (
Jude 1:1)
Is not this the carpenter's son? is not his mother called Mary? and his brethren, James, and Joses, and Simon, and Judas? And his sisters, are they not all with us? Whence then hath this
man all these things?
And they were offended in him. But Jesus said unto them, A prophet is not without honour, save inhis own country, and in his own house. (
Matthew 13:55-57)
And when the sabbath day was come, he began to teach in the synagogue: and many hearing
himwere astonished, saying, From whence hath this
man these things? and what wisdom
is this whichis given unto him, that even such mighty works are wrought by his hands?
Is not this the carpenter, the son of Mary, the brother of James, and Joses, and of Juda, and Simon?and are not his sisters here with us? And they were offended at him.
But Jesus said unto them, A prophet is not without honour, but in his own country, and amonghis own kin, and in his own house.
(
Mark 6:2-4)
Clearly, Jesus had siblings!