Wow. Was the temperature good in their house, did she drink and eat like normal? I wouldn't think the stress of moving would kill her, especially if she went with her mate. The closest thing I can think of that would come close is I know of a situation where a chinchilla was chased by a cat and although the owner got to the cat before it ever touched the chinchilla, the chinchilla just fell over dead. But that was an extreme trauma...nothing like a move. I would be more inclined to think there was something else going on.
