Nothing will be Impossible with God

To which tribe of Israel did Mary belong?
Judah (see Adam to Jesus).

To which tribe did Elizabeth belong?
She “was of the daughters of Aaron” (Luke 1:5), who belonged to the tribe of Levi, so Elizabeth was also of the tribe of Levi.

Then how can Elizabeth be a “relative” (Luke 1:36) of Mary?
συγγενης (suggenes), the original Greek word translated “relative,” can refer to a close relative or to anyone of the same kin or race, so Elizabeth can be a relative of Mary in the sense that they are both Jews. But given their age difference, the fact that they lived far away from each other and yet Mary spent about “three months” (Luke 1:56) living with Elizabeth, they are unlikely to have been just neighbors or friends. It is more likely that they were fairly close relatives, which is possible if Elizabeth's father had married a woman from the tribe of Judah, or Mary's father had married a woman from the tribe of Levi. (Jewish women had to marry men from their own tribe if they had no brothers and were their father's heirs; otherwise, they were free to marry men from another tribe (see Numbers 27:1-8 and 36:1-9).)

How “old” (Luke 1:36) was Elizabeth?
Since her conceiving a child should have been “impossible” (Luke 1:37), she was past her menopause.

How can a postmenopausal woman, let alone a virgin, conceive a child?
“For nothing will be impossible with God” (Luke 1:37).

What happened to Zacharias when he expressed doubt about the angel's words that his wife would conceive and give birth?
He was made mute for 9 months.

So why did Mary get off so easy?
Mary was a teenager, neither old nor knowledgeable nor a priest of Israel. She also hadn't been praying for a child as Zacharias had been.

After hearing the angel's explanation, what concern is likely to have come to Mary's mind?
'How am I going to explain this to Joseph, whom I am betrothed to marry?'

What example does Mary set for us?
When God instructs us to do something that doesn't fit our life's circumstances, immediately obey, and trust Him to work out the details.

Did He for Mary?
See Angel of the Lord.

Which Book has God's instructions for us?