God sent the Angel Gabriel to speak with the Virgin Mary to inform her that she was chosen to carry the Son of God. And although she was frightened, the angel assured her that by the power and grace of God all is possible. Mary worried because she was a virgin and to be engaged to Joseph.
As modern believers we may not understand why God chooses us for individual gifts. But that’s not for us to dwell on, His gifts are beyond our understanding. All we have to do is believe and know God’s word will never fail.