Standing by the cross of Jesus were his mother and his mother's sister, Mary the wife of Clopas, and Mary Magdalene. When Jesus saw his mother and the disciple there whom he loved he said to his mother, "Woman, behold, your son." Then he said to the disciple, "Behold, your mother." And from that hour the disciple took her into his home. (Jn 19:25-27)
https://bible.usccb.org/bible/readings/091523.cfm
The Octave of the Feast of the Birth of Mary is this feast of the Sorrowful Mother which is linked to yesterday’s feast of the Holy Cross. The church has always seen the Beloved Disciple as standing in for all of us, the beloved disciples of the Lord.

At the cross her station keeping,
Stood the mournful Mother weeping,
Close to Jesus to the last. (from the sequence hymn, Stabat Mater)