Luke 2

Yesterday, I noticed that as Luke began his record, he noted that -

"...as many have taken in hand to set forth in order a declaration of those things..." (New Testament | Luke 1:1)

"...Even as they delivered them unto us, which from the beginning were eyewitnesses..." (New Testament | Luke 1:2)

Obviously, Mary, the mother of Jesus, was an eyewitness of the events of the early days of the Savior's life. Luke specifically noted that with the events that surrounded the birth of the Savior that -

"...Mary kept all these things, and pondered them in her heart." (New Testament | Luke 2:19)

Later with the events that transpired at the temple as Mary and Joseph brought the babe to be presented to the Lord Luke specifically notes with after the prophecies of Simeon and Anna that -

"...Joseph and his mother marvelled at those things..." (New Testament | Luke 2:33)

And years later as the youthful Jesus "tarried behind in Jerusalem", His parents -

"...found him in the temple, sitting in the midst of the doctors, both hearing them, and asking them questions.
47 And all that heard him were astonished at his understanding and answers." (New Testament | Luke 2:46 - 47)

Again Luke provides some very personal insight that would only come from the parents as -

"...they were amazed: and his mother said unto him, Son, why hast thou thus dealt with us? behold, thy father and I have sought thee sorrowing.
49 And he said unto them, How is it that ye sought me? wist ye not that I must be about my Father's business?
50 And they understood not the saying which he spake unto them." (New Testament | Luke 2:48 - 50)

Again, Luke records that -

"...his mother kept all these sayings in her heart." (New Testament | Luke 2:51)

As we learn of the prophecies of Mary to Elizabeth, as we learn of the details of the events of His birth, and as we learn of these events of His youth, this information woould only most likely come from Mary. None of the other gospel writers mentioned any of these events. I would suspect from Luke's introduction to his record that all this history came directly from Mary, the most obvious resource - either by direct interview, but also as I believe, most likely in some sort of personal journal of Mary.