What did God see in her? Why did He raise up so lowly a girl so that all generations shall call her blessed (Luke 1:48)? Her "blessedness" does not come from something within herself. She is special because of what God has done to and for her, not through any magnificance of her own. The best explanation of the nature of Mary I've heard is where she is compared to the moon: like the moon reflects the brilliance of the sun, all of Mary's glory is merely reflected glory--as if anything connected to God can also be connected with such a word as "merely." Mary is amazing because God is so incredibly amazing. He (capital H) chose her (lower case h) to be His own mother, to be the Mother of The King.
And like Christ wasn't what the people of His day expected, a wordly power, a king (small k) who would kick those Romans rulers all the way back to Rome, Mary isn't what we'd expect in a Queen Mother! Her greatness is a small greatness--obedience, humility, quiet pondering, and a silent suffering witness to the Child of her body crucified. Any mother has wondered at images like the Pieta and thought, "As much as I could not bear it to hold my child, how much more awful for her to bear her Perfect Son and her God?!"
Pondering beyond that, how much more wonderful was her life? In my motherhood those first awkward steps, that first word, that first brilliant smile almost brought me to my knees with the joy of it. How could she have born the daily thrill of being in the presence of her God, humbled to become one of us and her baby! How extraordinary God makes the ordinary!

I just can't imagine it. I can't fathom it. As much as I am a mother, I feel in my bones her motherhood far surpasses mine. Her pains and even her joys and sweetnesses all have a weightiness mine will never approach. Being so close to God, His mother in fact, she reflects God's Glory that much more in all that she does. As close as I can ever come to that in my own motherhood is to reflect upon the most perfect mother I know--her. In that sense I am like a moon.
Let me be big enough to pray, my God, that I become small.