Where the other than normal things take place, they are mentioned.
Nothing is mentioned in this instance. It says simply that "she gave birth."
Anything other than the normal meaning of those words would be an addition to the text.
The argument from silence is a fallacy. And that is especially true when further information from Tradition is available.
-A8
But she gave birth to God in human form. The whole event is supernatural, although I am inclined in your direction since why else the nine-months in the womb if not to disguise himself. In any case. at one point in the script Mary and Joseph are wondering when he will reveal himself to them in all his power. Artistically, I would have used one of those newborns who from be beginning look you right in the eye, so that you know there is someone there.