What thoughts did Mary reflect upon? Were they sentimental? If you were having a baby in a real barn, sentimental thoughts would not be uppermost in your mind. Were Mary's thoughts contemplative, mystical, or profound? Possibly, but we have no reason to believe this. Were Mary's thoughts full of anger? Mary had reason to be angry since she was forced to have her baby in a stable, but we know that Mary did not sin. Therefore, if her thoughts were of anger, they were of righteous anger (see Eph 4:26).
Of course, no one can tell what was on Mary's mind. The only extended statement in the Bible on which to base any conclusions about Mary's thoughts is her "Magnificat." In Luke 1:46-55, Mary praised the Lord and then proclaimed a revolution. She prophesied: "He (the Lord) has shown might with His arm; He has confused the proud in their inmost thoughts. He has deposed the mighty from their thrones and raised the lowly to high places. The hungry He has given every good thing, while the rich He has sent empty away" (Lk 1:51-53). Mary called for a revolution not through physical violence but through repentance. This revolution was made possible by her Son Jesus, Who is a Sign of contradiction for the rise and fall of many (Lk 2:34).
For years, many of us have been making and breaking New Year's resolutions. Change an "s" to a "v", and make a New Year's revolution in Jesus. This will make "Happy New Year" not just a wish, but a reality.