I just received another comment on this post, which reminded me that I needed to update this story.
So the week after Friend spent the weekend with us, she disappeared off the face of the planet. Apparently she came to school on a Thursday, told some kids that she was packing up to move, was pulled from school early the same day, and hasn't been seen since. There is a for sale sign in front of her house.
PS is sure that Friend had no idea that she would be moving. How bizarre is this story?