27 [13:54-17:27] This section is the narrative part of the fourth book of the gospel.
28 [54] After the Sermon on the Mount the crowds are in admiring astonishment at Jesus' teaching (Matthew 7:28); here the astonishment is of those who take offense at him. Familiarity with his background and family leads them to regard him as pretentious. Matthew modifies his Marcan source (Matthew 6:1-6). Jesus is not the carpenter but the carpenter's son (Matthew 13:55), "and among his own kin" is omitted (Matthew 13:57), he did not work many mighty deeds in face of such unbelief (Matthew 13:58) rather than the Marcan "... he was not able to perform any mighty deed there" (Matthew 6:5), and there is no mention of his amazement at his townspeople's lack of faith.
Notice that it says in the footnote -- among his own kin, which to me means relatives -- not brothers or sisters.
My imprimatured Catholic Bible says clearly "brothers" and "sisters" and nothing about there being anything like "among his own kin" being omitted, which has no bearing on the meaning of the text anyway. What manuscript has that in it: Vaticanus B? Sinaiticus? or some other obscure corrupted text?
There is no footnote in my Catholic Bible that says that these brothers and sisters were anything other than what it says they were: brothers and sisters. And we both know that if they were not children of Mary, then they could not have been brothers and sisters of Jesus, right?