But assume gratuitously that these women were the same relatives of Jesus referred to in Mark 3:21 :In Galilee these women had followed him and cared for his needs. Many other women who had come up with him to Jerusalem were also there.
Then these women are not true disciples: at least, surely they don't know who is really Jesus. They may have even bad intentions about him.When his family heard about this, they went to take charge of him, for they said, “He is out of his mind.”
If my hypothesis is correct (the women of Mark 16 being the same "family" of Mark 3) then we are arrived at a turning point of the story: who in Mark 3:21 was searching for Jesus without never be able to arrest him (because of the "wall" represented by the crowd of listeners around Jesus) are going finally to conquer his body in Mark 15:41, after so much labor. Even the sudden apparition of Joseph of Arimathea seems an other obstacle for them from this respect. So the stone before the tomb serves as a protective function against them, because otherwise they can conquer Jesus.
But then, just when these women can conquer the body of Jesus, their diabolic plan is defeated: so these women are allegory of the rulers of this age, since they realize who is Jesus (basically: not who they believed him be until that moment) only at the end.
So the family of Jesus is really condemned by their fugue en masse. The point is reiterated just at the end of the Gospel that Jesus is basically without a carnal family in Mark.
This explains why Mary in Mark 15 & 16 is never called mother of Jesus: she is basically not the true mother of Jesus even if she believes wrongly so.