Luke 1:
26 In the sixth month the angel Gabriel was sent from God to a city of Galilee named Nazareth,
27 to a virgin betrothed to a man whose name was Joseph, of the house of David; and the virgin's name was Mary.
28 And he came to her and said, "Hail, full of grace, * the Lord is with you!" *
29 But she was greatly troubled at the saying, and considered in her mind what sort of greeting this might be.
30* And the angel said to her, "Do not be afraid, Mary, for you have found favor with God.
31* And behold, you will conceive in your womb and bear a son, and you shall call his name Jesus.
Good point.
The thing is, though, that in verse 38, Mary says:
Mary said, “Behold, I am the handmaid of the Lord. May it be done to me according to your word.” Then the angel departed from her.
My reading of this is that, while Gabriel laid some pressure on her, she accepted. Gabriel didn’t leave until she had agreed to the task and the role assigned to her. Now if she had declined, what would have happened? Hmmm.