John 12 actually takes up a narrative about Mary, Martha, and Lazarus which began in John 11. These three persons personify three kinds of belief. Martha acknowledges the identity of Jesus as the Messiah, Lazarus has experienced the awesome power of Christ’s resurrection power. Their responses to Jesus personify faith and Hope.
Mary sees something in chapter 11 that the others do not see. She sees Jesus weep. Confronted by the heartbroken, suffering Christ, Mary personifies prodigal, unfettered love.