Considering how She was created by God to be (see below), and remained thus of Her own free will, it would have been uncharacteristic for Her to choose to disobey God the Father.
Jesus said:
"The Supreme Mind, that knows everything, before man existed, knew that man would be a thief, and self-murderer. And, as the Eternal Goodness has no limits in being good, before Guilt existed, He thought of the means to obliterate Guilt. The means: I, the Word. The instrument to render the means an efficient instrument: Mary. And, the Virgin was created in the sublime mind of God.
The sublime victory of God over Satan's revenge was to raise the perfection of the beloved creature to a super-perfection that should annul at least in one person all recollection of humanity, liable to Satan's poison, so that the Son should be generated not by a man's chaste embrace, but by a divine embrace that causes the spirit to change color in the ecstasy of the Fire.
The Virgin's Virginity!...
Come. Contemplate this deep virginity that gives ecstatic dizziness in its contemplation! What is the poor enforced virginity of a woman that no man married? Less than nothing. What is the virginity of a woman who wanted to be a virgin to belong to God, but is so in her body, and not in her spirit, where she allows alien thoughts to enter, and entertains allurements of human thoughts? It is a sham virginity. But, still very little. What is the virginity of a cloistered nun who lives only for God? Very much. But, it is never the perfect virginity when compared with My Mother's.
There has always been an association, also in the most holy one. The original association between spirit and fault. The one that only Baptism dissolves. It dissolves it, but as in the case of a woman separated from her husband by his death, it does not render virginity complete such as it was in the First Parents before sin. A scar remains, and hurts causing one to remember it, and it is always ready to become a sore, like certain diseases that periodically are made worse by their virus. In the Virgin there is no sign of this dissolved association with the Fault. Her soul appears beautiful, and intact as when the Father conceived Her, gathering all graces in Her.
She is the virgin. She is the Only One. She is the Perfect One. The Complete One. Conceived as such. Generated as such. Remained such. Crowned such. Eternally such. She is the Virgin. She is the acme of intangibility, of purity, of grace that is lost in the Abyss from which it emerged: in God: most perfect Intangibility, Purity, Grace.
That is the revenge of the God Trine and One. Against creatures desecrated He raises this Star to perfection. Against pernicious curiosity He raises this Coy Virgin, contented only with loving God. Against the science of evil, this sublime Innocent Virgin. In Her there is not only no knowledge of dejected love: there is not only non-acquaintance with the love that God had given to married people. Much more. In Her there is the absence of incentives, the inheritance of sin. In Her there is only the icy, and white-hot wisdom of divine love. A fire that strengthens the flesh with ice, so that it may be a transparent mirror at the alter where God married a Virgin, and does not lower Himself because His perfection embraces Her perfection, which, as it becomes a bride, is only inferior to His by one point, subject to Him as a Woman, but without fault as He is." (
The Poem of the Man-God: Volume I, by Maria Valtorta)
Now, it was said by the prophet, Isaiah, the Savior would be born of a virgin (7:14). This becomes a condition for fulfilling the prophecy. If she were not a virgin, then this would not be a valid prophecy.
Regarding the Blessed Virgin Mary, and the idea she had other children, first, the words "brother" (
ἀδελφός, Adelphos),"brothers" (
ἀδελφοὶ, Adelphoi), "sister", and "sisters", have a range of meanings. Therefore, those who believe Mat. 13:55-56 and Mk. 6:3, for example, proves Jesus had biological siblings should explain why the context surrounding the word "brothers" and "sisters" in those verses supports the "biological siblings" definition specifically, rather than any of the others.
I would argue they do not for the following reasons: in Mat. 13:55 and Mk. 6:3, Simon, Joseph, James, and Judas Thaddeus are identified as brothers. In Mat. 10:3, Mk. 3:18, Mk. 15:40, Lk. 6:15-16, and Acts. 1:13, James, and Judas Thaddeus, are again identified as brothers, but also as the sons of Alphaeus, and Mary. In Jn. 19:25, the Blessed Virgin Mary, and Mary of Cleophas, are identified as sisters, and the name "Alphaeus" is a variant of the name "Cleophas". Therefore, the Blessed Virgin's sister-in-law, Mary, was the wife of Alphaeus, St. Joseph's brother, and their sons were: Simon, Joseph, and the apostles James (the Less, the brother of the Lord), and Judas Thaddeus, thus Jesus's cousins. The sisters of Jesus refer to women disciples.