I'm not convinced about the "pains of childbith" angle. Our Lord and Our Lady took on many of the sufferings that they would normally have been exempt of due to being free from Original Sin. Suffering and death in general are the consequences of Original Sin, but they willingly accepted them anyway. I didn't watch this movie nor do I intend to, but if they depiced Our Lady as screaming/shreiking, etc., then that would be completely out of line, as I'm sure she bore whatever suffering she did experience with full dignity.
I agree in principle with this. And I would add also that suffering and death are natural to man even abstracting from sin. Integrity, impassibility, immortality, infused knowledge... these are praeternatural gifts which were given to Adam and Eve in connection with original justice. The nexus between these gifts and original justice itself is debated by theologians, and either way the justice of our Lady ks not identical with the original justice of Adam and Eve and does not necessarily imply the praeternatural gifts. In fact this ties in with our Lady's death. A few modern theologians including Guerard Des Lauriers, following the lead of Roschini, hold the novel opinion that Our Lady did not suffer death. They too use the argument that death is a punishment for sin. However not only does this disregard all of tradition in East and West, but it also ignores the positive aspects of suffering and death, abstracting from sin as well as the fact that suffering and death are both in fact natural to man. Greater love hath no man than to lay down his life for his friends...
I believe with Scheeben that our Lord (and our Lady although he doesn't say that part) had the gift of integrity, which he describes as the complete subjection of all lower faculties (including sense as well as bodily functions, the collapse of which leads to death) to the will. Thus Jesus' suffering and death were perfectly compatible with the gift(s) since he only suffered and died insofar as he willed it. We can say the same for our Lady.
However as to the pains of child birth, it doesn't seem tenable to me to ascribe them to our Lady. Since she was and is always virginal, I don't know where the pains would be coming from... her physical virginity being intact during birth necessitates a miraculous birth and however we choose to describe that, it would seem to me that the physical pains of the birth canal, etc could only apply to a process which would rupture the physical virginity of a woman. I don't want to be graphic here but I don't understand mechanically whence the pains would derive if not from the typical physical process of birth. Still in principle our Lady suffering pains typically seen exclusively as a punishment for sin is no problem theologically at all.