Think about this. If an angel of God came to you and said you were going to have the Son of God what would you do? Would you, after having the Son of God, go and have other children? And as such, end up having to split your time up between all these children. Or would you, instead, devote your entire life to raising and caring for the Son of God and forgo the gift of having other children? There by devoting your whole life to the care and raising of God’s Son.
I think one thing that has been forgotten is that children are a gift from God. As with all gifts, some of us well receive this gift and some of us will not. After all doesn’t Scripture state that we do not all receive the same gifts? Some will have children and some won’t. Also as Scripture states some will be made eunuchs by man, some are born eunuchs, some make themselves eunuchs for the Kingdom of God. Mary and Joseph gave up the gift of having earthly children for the sake of the gift of the heavenly Child.
St Paul pegs this down really well in
1 Cor 7:
Those who have an earthly marriage do well, but those who forgo the earthly marriage for the sake of the heavenly marriage do better. In the case of Mary and Joseph, they did better than the rest of us.
Another chapter to think about is
Numbers 30.