First off, I don't know if Elizabeth Lerner's UU World Article correctly portrays what goes on in the book. I haven't read the book.
But the movie version makes her LOOK wrong.
Lerner seems rather huffy about the fact that according to the Gnostic gospels, Mary was a religious leader, not just a wife and mother. The movie very clearly states that this was the case and that Mary was more or less left in charge. The Knights templar seem to regard her, and not any male descendents she might have had, as a Pope-like figure. The movie shows women religious leaders and free thinkers being carted off and burned as witches, making very clear the point that women have always stepped up into leadership roles, they just kept getting killed for it for awhile.
In fact, when Sophie is revealed to be Jesus' last remaining descendent (assuming the Grandmother you see at the end is on the other side, which I think we're supposed to) she is very clearly charged with doing God's work and deciding the destiny of the church on earth. Nobody even mentions that she should go out and make more Jesus babies, and to me it would have been fairly forgivable if they had, considering that is typically priority one for heirs.
Also, I saw the Sophie-as-Jesus-descendent thing coming like an hour into the movie. But "Apple" was cool.
This movie was quite heavy on the Gnosticism, and did much to promote some suckily ahistorical ideas. But it was interesting to see the "Jesus as a regular guy" concept presented and wonder what was going on in the heads of the people seated around me.