God was about to break into the world in human flesh. His plan included working through the life of a teenage girl. It is interesting that in a patriarchal society, the angel visited Mary first. He did not visit Joseph first to get his permission. He did not discuss God's plan with Joseph and ask if he was willing to go along with it. Nor did Mary put the angel's message on hold and go to ask Joseph what she should do before responding.
Mary did not need to get Joseph's permission or submit to his authority. She had God's word, God's authority. That was enough for her. Mary was willing to submit to God's will with or without Joseph. She had no idea what Joseph's response would be. She had no idea what he would do. The decision was hers and hers alone to make. She was called on by God to do his work and she willingly submitted. She was willing to face the humiliation, ridicule, and rejection of pregnancy before marriage — alone if need be.
That does not mean that Mary did not need Joseph. She needed Joseph's love, his support, his understanding, his willingness to serve God alongside her, his partnership, his protection in a patriarchal society. She needed him to walk the journey with her. But, when she responded with a resounding yes to the angel, she did not have the assurance that Joseph would stand with her when she accepted God's call on her life. But, she did not need his permission to do what God called her to do. Joseph was told after the fact, and he willingly submitted to God's call on Mary's life. He stood with her, supported her, and encouraged her. Joseph was Mary's "ezer kenegdo" — her "suitable helper." --dona