There are monsters in the desert. They came from the sea and fought with man, but now they wait, picking off their victims one at a time until they see fit to rage against the world of man once more.
As Lo-Melkhiin rides the storm into Her (there are no names in the book except for Lo-Melkhiin) village, She knows that he is coming to claim a new bride and her beautiful sister will most likely be his pick. Lo-Melkhiin has had three hundred brides already, and each one has met a swift death.
Without a second thought, She makes it so there is no other choice but to pick Her as his bride