C3PX,
I will attempt to summarize:
1. Definitely say, "But you can just get another one!" It sounds like a real winner. Though I'm not sure what you can say when she shouts, "But I DON'T want another one! I just want ***** back! Boo hoo hoo!" That seems pretty iron clad. I guess just hope she doesn't say that.
Actually that's probably all of the advice you'll need. Most of the time I've found honestly saying "Wow, I have no idea what you're going through because I have nothing to compare it to." to be of more service than trying to stretch anything like, "I remember when my first NES stopped working. I cried for days." or something like that.
Seriously though... I don't mean to single you out 005, but the "my pets are my kids" sentiment really rubs me the wrong way. It's usually opined by people that don't have kids... and I guess they must really misunderstand what having kids is like. I can understand being very attached to an animal... but nothing like actually having (human) kids. Though having a (dog) puppy is probably very similar to having a (goat) kid. Maybe that's what is meant.