In her book of divine revelations and prophecies (Revelations III, 8), Saint Bridget of Sweden quotes Mary as saying:
”I am the woman who has always been in God's love. I was from my infancy entirely in the company of the Holy Spirit. If you want an example, think of how a nut grows. Its outer shell grows and widens, while its inner kernel also widens and grows, so that the nut is always full and there is no room in it for anything extraneous. In the same manner, too, I was full of the Holy Spirit from my infancy. As my body grew and I became older, the Holy Spirit filled me up with such abundance that he left no room in me for any sin to enter. Thus, I am she who never committed either venial or mortal sin. I so burned with love for God that I liked nothing but to carry out God's will, for the fire of divine love blazed in my heart.
God, blessed above all forever, who created me through his power and filled me with the power of his Holy Spirit, had an ardent love for me. In the fervor of his love he sent me his messenger and gave me to understand his decision that I should become the Mother of God. When I understood what the will of God was, then, through the fire of love that I bore in my heart towards God, a word of true obedience at once left my lips, and I gave this answer to the messenger, saying: 'May it be done to me according to your word.' At that very instant the Word was made flesh in me. The Son of God became my son.
The two of us had one son who is both God and man, as I am both Mother and Virgin. As my Son Jesus Christ, true God and wisest of men, lay in my womb, I received such great wisdom through him that I not only could understand the learning of scholars, I could even discern whether their hearts were true, whether their words proceeded from love for God or from mere scholarly cleverness.”
Saint Bridget of Sweden, Revelations (VIII, 8)