The Pope is actually supporting the historical nature of the parts of the Gospels which talk about the Annunciation, the Nativity, Mary’s perpetual virginity, Joseph’s stature as a just man, John the Baptist as a baby, and Jesus being found in the Temple.
To do this, the Pope examines various ways that people have studied the stories and genealogies, points out which ideas seem to be true or untrue or only partially helpful, further points out stuff that we don’t really know enough about to have an opinion, and talks about why we shouldn’t be too worried if some things in the Bible are not perfectly understood by us. (He points out that there are plenty of prophecies and happenings in the Bible which weren’t understood, or weren’t seen with their true meaning, for hundreds or thousands of years. That’s how some prophecy works. It’s addressed to people in the future, not the people right now.)
If your mother reads the whole book, instead of reading articles about the book or only excerpts from the book, she’ll understand what he’s doing.
If she reads the other two books, she’ll have a little more familiarity with the Pope’s way of making his points. (He loves to quote things he agrees with from people he disagrees with, or turns their disagreed-with argument into something one can agree with, or just puts out a lot of different evidence until he finally brings it together and makes his point.)
