What Mary went through is something we face. She was skeptical.
She considered what Gabriel said.
Zacharias was also skeptical before Gabriel, even being a priest and someone who should know.
“How can I be sure of this? For I am an old man; my wife is too well on in years.”
The difference between Zacharias and Mary is her skepticism manifests as a curiosity, his manifests as disbelief.
“How can this be?”
“I am advanced in years”
Zacharias was supposed to be wise to the workings of God, being a priest. Mary had no education or preconception. Mary's curiosity finalizes with belief. Gabriel did not punish her before leaving her presence, yet he did with Zacharias as he should have known better.
Mary believed Gabriel not only about herself but also her cousin. Gabriel didn't talk to Elizabeth, yet the Holy Spirit came upon her. Both her and the unborn John knew and confirmed what Mary was told by Gabriel of her calling and destiny.
You must trust and believe what God is calling and placing on your life. Even though Mary's cousin was a priest, she believed the destiny and calling was from God. She trusted He would supercede His Law, which the priests are charged to uphold. Zacharias, as priest, was charged to report any known break of the Law. Yet after his meeting with Gabriel he knew God's power and his little cousin's call.
Especially as a young woman where the penalty is summary execution by stoning, if you were party to something not legal, the last place you would go or run with haste is a priest.