There were babies in Brazil just born like this. I had never heard of these two. I'm wondering how they eat. It's one thing if they're eating something that requires one hand to hold, but what if they're cutting a steak, how do you decide who gets what piece?
So below the waist, how do the nerve connections work? Is there a splitter sending signals to both brains? That's what puzzles me...
If they're old, the survivor would probably be too weak to last the split, you may even have doctors claiming letting her live or making the split is inhumane or something. If they're young, that means there was an infection; I can't think of a lot of those that would affect one and not the other.