Now that I look at the image, it appears that the stars are arranged in a grid-like pattern, and not randomly as they would appear in the sky.
Also, I wondered how you can tell that she is pregnant, since there doesn't appear to be any form to her garments.
The Jewish tradition is the black ribbon or band around her waste (her womb). You have to find a Biblical expert to contradict me on that one, as I got it from reading several books on Guadalupe and that this was where the black "belt" (for lack of a better word) meant -- she is pregnant, and has special honor in Jewish society of the time of Christ.
This is why Jesus NEVER SPOKE OF ABORTION. Having children was always valued in Jewish tradition. Rachel lamenting how barren she is, for example. And the rejoicing at the birth of children in the Old Testament.
Father Mitch Pacwa would be a good source if I could pull some favors with some Jesuits who know him.