the swords of her dolours
an oblique reference to the Seven Dolours (or Sorrows) of the Virgin Mary, pictures of whom adorn Lady Marchmain’s rooms. Such a picture would show the Virgin with her heart pierced by seven swords. In Fez Sebastian will have a picture of the Seven Dolours in his hospital room at which he will look when he hears that his mother is dying.
The Seven Dolours are :
The prophecy of Simeon (Gospel of St Luke 2, 34-35);
The flight into Egypt (Gospel of St Matthew 2, 13-15);
The loss of the Child Jesus in the temple (Gospel of St Luke 2, 44-50);
Jesus and Mary’s meeting on the Way of the Cross (implied, Gospel of St Luke 23, 27-31);
The Crucifixion (all gospels);
The taking down of the Body of Jesus from the Cross (all gospels);
The burial of Jesus (all gospels).
The point is not that Lady Marchmain is a modern type of the Virgin Mary, a thought she would consider blasphemous; but that she offers up her sorrows to God as a sacrifice in the way that Mary did.