That's because Demontfort also says:
3. In answer to her prayers to remain hidden, poor and lowly, God was pleased to conceal her from nearly every other human creature in her conception, her birth, her life, her mysteries, her resurrection and assumption. Her own parents did not really know her; and the angels would often ask one another, "Who can she possibly be?", for God had hidden her from them, or if he did reveal anything to them, it was nothing compared with what he withheld.
4. God the Father willed that she should perform no miracle during her life, at least no public one, although he had given her the power to do so. God the Son willed that she should speak very little although he had imparted his wisdom to her.
Even though Mary was his faithful spouse, God the Holy Spirit willed that his apostles and evangelists should say very little about her and then only as much as was necessary to make Jesus known.
6. I declare with the saints: Mary is the earthly paradise of Jesus Christ the new Adam, where he became man by the power of the Holy Spirit, in order to accomplish in her wonders beyond our understanding. She is the vast and divine world of God where unutterable marvels and beauties are to be found. She is the magnificence of the Almighty where he hid his only Son, as in his own bosom, and with him everything that is most excellent and precious. What great and hidden things the all-powerful God has done for this wonderful creature, as she herself had to confess in spite of her great humility, "The Almighty has done great things for me." The world does not know these things because it is incapable and unworthy of knowing them.
I wonder where that guy got all that nonsense?