Mary was not only chosen by God to give birth to Jesus but to be his human mother also. Being devout in the Hebrew faith she would raise him in the nurture and admonition of the Lord (think, spiritually, God knew this when he picked her?). The Son of God in Jesus didn't need this but the Son of Man did (Hebrews 2:17&18). The perfect mind of Christ in Jesus kept him from sinning. Christians strive to have this perfected mind of Christ
(1 Corinthians 2:16, Philippians 2:5) .

So Mary's job was to be the mother of Jesus the human (Son of Man). Not to raise the Son of God or tell anyone who he was until His time had come, these things were between God the Father (whom Jesus says he listens to in several places in scripture) and Jesus Christ.

This is brought out in recorded scripture encounters between Jesus and Mary and by the reaction of Jesus's Nazareth neighbors and His siblings as to who He was or wasn't.

Encounter 1. The boy Jesus in the temple (Luke 2;41-52). Here Mary is doing her justified frustrated mom thing chewing out her puberty 12 yr old (human) son for making them worry. Typical natural behavior 12yr old boy thing to show off how much He already knows. What is interesting is how some say Mary forgot that Jesus was God's son. Mary didn't forget who He is, she knew full well who He is she pondered those things in her heart-ingrained them - remember. They get this from Luke 2:50 "And they did not understand the saying that He spoke to them." It wasn't that Mary didn't get the gist of what He was saying, she knew she wasn't finished doing what God had assigned her to do, raise the boy in the nurture and admiration of the Lord, and she expected Him to toe the line. What she didn't understand is why He was saying this now. Jesus got the message also Luke 2:51 "And he went down with them and came to Nazareth and was submissive to them. And his mother treasured up all these things in her heart." God spoke through Mary, it wasn't time for the Son of God to come out, and Jesus knew it - “Honor your father and your mother, that your days may be long..."

Encounter 2.The wedding at Cana; John 2:1-11. This occurred after Jesus had been baptized, John announced Him as the Lamb of God and Jesus started picking up his disciples. Mary would have known about this because she was at the wedding as well with Jesus and his new disciples.
It was now apparent that Jesus, after 30 yrs, was launching his ministry. Now Mary who hadn't said a peep to anyone about Jesus being the Son of God felt inspired to tell Jesus the party was running out of wine. We know from scripture Mary didn't tell her neighbors in Nazareth or even her other children (Mathew 13:55-57) that Jesus was also the Son of God - they had no clue. It is apparent Mary brought up Jesus in the same manner as his siblings not showing favoritism.

So this time, Jesus tells her 'my time has not yet come' but at 12 he was ready to rip! Mary follows her inspiration and tells the servants do what ever he tells you. Again God speaks through Mary. Jesus gets the message and now knows it is time to come out. He tells the servants to pour water into the water jars, the water becomes wine, and he tells them to serve the wine.

Encounter 3. (Mark 3:1-6) Sometime after the Pharisees started plotting with the Herodians against Him, how to destroy Him, Jesus was speaking to a crowd in His home town. Where they were already questioning the truthfulness of Him. "And when His family heard it, they went out to seize Him, for they were saying, “He is out of his mind.”Mark 3:21. They were afraid for His safety, many influential people were plotting to destroy Him
Many read this and think Mary and his brothers thought Jesus was crazy without reading the preceding text and other threatening text against Jesus. In Mark 3: 31-35 He is letting His mom know that this is His mission He now belongs to all who will accept Him not just to them. He is now totally in God the father's hands as to what will happen to Him she needs to let go now and let God.

Encounter 4. From the cross Jesus spoke His last words to His mother and told John to take care of Her (John 19: 25-27). He now returned the blessing to His mom for the many blessings she gave Him in raising Him.

From the humbleness, praise and understanding of what God has done not only for her but all mankind, expressed in her Magnificat (Luke 1:46-55), we know Mary clearly understood her place in God's grand plan:

Luke 1:
46 And Mary said,“My soul magnifies the Lord,
47 and my spirit rejoices in God my Savior,
48 for He has looked on the humble estate of His servant.
For behold, from now on all generations will call me blessed;
49 for He who is mighty has done great things for me,
and holy is His name.

She was God's good and faithful servant and rejoiced in the opportunity not only to give birth to Jesus but to be his mom. There was a great, special, loving and understanding relationship between God the Father, Jesus Christ and Mary. This is her unique blessing through time and the life she now enjoys with God her savior Amen.