In Luke 8:21, after Jesus was told His mother and brethren were standing outside desiring to see Him, He replied:
“My mother and my brethren are those who hear the word of God and do it.”
Now, at first reading, this might seem to be an insult to Mary, His mother, but we know Jesus is God and that He follows His own commandments. Rather than an insult, this is an honor. Don’t read this is as Jesus saying “I don’t have a mother,” nor “I care more for people who do my will than I do my own mother.” Rather, we can see in Jesus’ words a special honor for Mary’s docility to the will of God.
The Golden Chain quotes St. John Chrysostom as commenting on this passage:
Now He does not say this by way of reproof to His mother, but to greatly assist her, for if He was anxious for others to beget in them a just opinion of Himself, much more was He for His mother.
Read: Mary and my brethren (relatives–cousins, aunts, uncles, etc.) are among those who hear the word of God and do it.
In fact a few chapters later, Jesus again highlights Mary’s obedience again. Lk 11: 27-28:
27 As he said this, a woman in the crowd raised her voice and said to him, “Blessed is the womb that bore you, and the breasts that you sucked!”28 But he said, “Blessed rather are those who hear the word of God and keep it!”
Mary is certainly blessed among women for being the Mother of God. Jesus doesn’t reject that; rather He emphasizes how Mary is even more blessed because she perfectly kept God’s word (she did the will of God).