Having experienced two natural labors without pain meds, I know it can be scary and painful. I can't imagine how she felt, going through labor for the first time, and in a "barn" nonetheless. I doubt she and Joseph had gone through childbirth classes or had a doctor there to catch the baby.
The angel had come to her earlier and told her she would conceive through the Holy Spirit. I think she knew that she was the virgin whom Isaiah had prophesied would deliver the Messiah to the world. But, did she really foresee the pain and agony she'd experience 30 years later when people rejected her son's teachings and later crucified him on the cross? Did she fully understand that her little baby was the Son of God?
I love what Mark Lowry writes at the end of his book based on the song:
By believing on the Lord Jesus Christ, we are saved.
Peter had to believe for himself. Thomas had to believe for himself. James and Jude had to believe for themselves. Mary, the mother of Jesus, also needed a savior. She had to believe for herself. And because we have chosen to believe in the virgin-born, crucified and risen Savior, Jesus Christ, we know we have received eternal life.
And this, for sure, Mary knew.
Mark Lowry singing "Mary Did You Know?"
Mary did you know that your baby boy will one day walk on water?
Mary did you know that your baby boy will save our sons and daughters?
Did you know that your baby boy has come to make you new?
This child that you've delivered, will soon deliver you.
Mary did you know that your baby boy will give sight to a blind man?
Mary did you know that your baby boy will calm a storm with his hand?
Did you know that your baby boy has walked where angels trod?
And when you kiss your little baby, you have kissed the face of God.
The blind will see, the deaf will hear and the dead will live again.
The lame will leap, the dumb will speak, the praises of the Lamb.
Mary did you know that your baby boy is Lord of all creation?
Mary did you know that your baby boy will one day rule the nations?
Did you know that your baby boy is heaven's perfect Lamb?
This sleeping child you're holding is the great I Am.
Praise to the GREAT I AM, and a Merry Christmas to you all!