One traditional way of thinking of Mary is as a model.  In the story of the Annunciation Mary appears as a model for us in a special way.  She models how to respond to God’s invitation i.e. with complete submission to his will.

In his account tells us an angel, Gabriel, was sent to Mary to announce to her that she was to be the mother of the savior.  According to Luke’s description, it wasn’t a question of Mary being given a kind of mental message.  Mary encountered Gabriel and entered into a conversation with him.  An important question is how did she know it was an angel.
The only possible answer is a striking one.  She knew it was an angel in the same way that we, in our lives, can recognize a message from God.  How do we know when a thought, a meeting, a happening is a message from God?  That problem is exactly the same problem had to resolve for herself.

What did Mary do?  Her reaction to Gabriel’s words is an instance of how Mary is a model for us.  It is clear that in responding she avoided two possible extremes: believing the message immediately without reflection or rejecting it out of hand.  The first could lead to illusion and error.  The second could effectively close off the possibility of ever receiving a message, a call from God.

Mary took her time.  One interpretation of Luke’s account is that he has condensed into a few dramatic moments a process that actually took much longer.  There is nothing in the account to prevent us from understanding it in that way.

Mary’s was truly an extraordinary call, a unique vocation.  It was a vocation to fill a unique and crucial role in the history of salvation.  God chose to have it hinge on the free choice of a humble Jewish maiden.

We are told Mary pondered Gabriel’s words in her heart.  The words of her Magnificat show that she sought to understand the meaning of what happened to her in the light of the prophets. The image of Mary that emerges from this scene is that of someone especially favored by God; someone thoughtful, obedient, believing, and worshipful.
Perhaps Mary’s most important quality was her openness to God’s will.  After she came to      the conclusion she was truly being called by God, she made an act of complete trust in God, submitting herself entirely to his will.

Obviously, our call, our vocation is very different from Mary’s.  But we are called to imitate the faith and openness and generosity of Mary in our response.