Luke 2:19-20, 33-35
"But Mary treasured up all these things and pondered them in her heart. The shepherds returned, glorifying and praising God for all the things they had heard and seen, which were just as they had been told."..."The child's father and mother marveled at what was said about him. Then Simeon blessed them and said to Mary, his mother: 'This child is destined to cause the falling and rising of many in Israel, and to be a sign that will be spoken against, so that the thoughts of many hearts will be revealed. And a sword will pierce your own soul too.'"
Mary had so many unusual experiences as a very young woman. She was visited by an angel, was pregnant before being with her husband, traveled to Bethlehem being very pregnant, went into labor and had her first child born in a stable, was visited by shepherds from the fields announcing their visit from the angel, and now hearing of things to come with her child.
So much for a young woman to take in. But Mary was chosen by God. He knew her heart and she trusted him. She surrendered her will to His and was faithful to what God had called her to do. The road before her would not be easy. God never promised easy. He promised a Savior and God is faithful to do what He promised, even if life looks like it is filled with trials. God is not surprised. He has a purpose and a plan...and it is Good.