I had always heard that we picked who our parents were going to be in the Pre-existence. And then on the other hand I was told that we could have married ANYONE and had children and been happy. So did we know that we were going to come to the family that we were born into?
I don’t know about every spirit who comes into mortality, but I do know that there are those who are foreordained to come through certain lineages to which they are entitled. For instance, we read in the book of Abraham in the Pearl of Great Price the following:
Now the Lord had shown unto me, Abraham, the intelligences that were organized before the world was; and among all these there were many of the noble and great ones;
And God saw these souls that they were good, and he stood in the midst of them, and he said: These I will make my rulers; for he stood among those that were spirits, and he saw that they were good; and he said unto me: Abraham, thou art one of them; thou wast chosen before thou wast born. (Abraham 3:22-23)
Those who are of the House of Israel, and many are aware of who they are, as is revealed in their patriarchal blessings, have been foreordained in the spirit world to be born into that special lineage.