Monks have a devotion to Our Lady, the Blessed Virgin Mary, because she is an extraordinary model of perfection and holiness. She embodies the goal of the monk. This is so in three big ways: humility, obedience, and prayer.
Humility: "How can this be, since I am a virgin?" Mary, God's most humble creature, glows with humility, that virtue of virtues. The monk is captivated by this, because humility forms the center of his spirituality. The higher he climbs on the ladder of humility, the closer he gets to God.
Obedience: "Here am I, the servant of the Lord; let it be with me according to your word." To God's great delight, Mary bowed to his wish promptly, without reservation, and with great trust. What's more, she remained obedient throughout the great trial of her son's Passion. The monk is awed by this, because obedience is the vow with which he struggles the most. In fact, obedience constitutes three rungs on the ladder of humility.
Prayer: "Mary treasured all these words and pondered them in her heart." From the moment of Jesus' conception, she lived with the mystery that her son was the Son of God, the Savior. She gazed upon God. The monk envies such a privilege, as he yearns for the gift of contemplative prayer.
Since Mary is our heavenly Mother, she is the Mother of Monks. Through her prayer she protects, guides, and intercedes for the monk. She does this in a special way, because the monk shares something special with Mary: both have been called to an extraordinary vocation.