The trouble with reading the Bible, as one is supposed to do at this time of the church year, is that it is far too easy to slip into actually thinking about what you are reading.
Meanwhile, standing near 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 whom he loved standing beside her, he said to his mother, “Woman, here is your son.”
Then he said to the disciple, “Here is your mother.”
And from that hour the disciple took her into his own home.
Bearing in mind that in both Hebrew and Aramaic, gender applies to the role of something rather than its appearance, it is very possible that Mary Magdalene is "the beloved disciple" that Jesus talks to from the cross and that he is assigning her the role of looking after his mother like a good son (which, after his death, he can no longer be) would do in their culture. This makes sense of the text without having to add another character to those mentioned in the first sentence. It would also make sense of the Last Supper mention of the beloved disciple and the pretty, young lady next to Jesus in that Da Vinci painting.
Dammit! Dan Brown might be right after all. Or, rather, the people he nicked the idea off (allegedly) may be right after all.