Fr. Gabriel of St. Mary Magdalene writes,

“The Blessed Virgin teaches us to believe in our vocation to sanctity, to divine intimacy. We did believe in it when God revealed it to us in the brightness of interior light, and the words of His minister confirmed it; but we should also believe in it when we find ourselves alone, in darkness, amid difficulties that tend to disturb and discourage us. God is faithful, and He does not do things by halves: He will finish His work in us, provided we have complete confidence in Him.

It would be very far from the truth to think that the divine mysteries were so revealed to Mary, and the divinity of Jesus was so evident to her that she had no need of faith. Excepting the Annunciation and the events surrouning the birth of Jesus, we do not find any extraordinary Faith manifestations of the supernatural in her life.

Mary lived by pure faith, trusting in God’s word even as we must. The divine mysteries which took place in her and around her remained habitually hidden under the veil of faith, assuming an outward appearance common to the various circumstances of ordinary daily life. Hence, they were often concealed under obscure, disconcerting aspects such as the extreme poverty in which Jesus was born, the necessity of fleeing into exile in order to save Him, the King of heaven, from the wrath of an earthly king, the toil undergone to
procure for Him the strict necessities, and the lack of even these, perhaps.

Yet Mary never doubted that this weak, helpless Child, who needed her maternal care and protection just like any other child, was the Son of God. She always believed, even when she did not understand.” 

— Fr. Gabriel of St. Mary Magdalene, Divine Intimacy, Mary’s Faith.