After Gabriel told her that she would be the mother of the Promised Savior, the Son of God, Mary asked a simple question. “But how can this happen? I am a virgin.” Mary's question stands in contrast to what Zechariah asked when he was told his wife would have a son. “How can I be sure this will happen?" Mary knew that virgins did conceive and give birth to a child on their own. Zechariah had doubts and asked how he could know for sure.
Gabriel told Mary her child would be conceived by the Holy Spirit. Jesus would be her child, a human being. Jesus would also be the Son of God. Jesus is both God and man. He is the Promised Immanuel, God with us.
When God answers our questions, we need to listen, believe, and trust God. That is what Mary did. God sent the angel Gabrielle, His messenger, to Mary. God sent His Son to us. Jesus is our Prophet who speaks to God for us. We can listen to Him when we read His Word in the Bible.
Like Mary, we don't always know how God is going to keep His promises, but we know He will. I think it is ok to ask God questions. But don't forget to listen for His answer.