It's a long shot but is she anywhere near upstate NY? I have one I can lend to her.

Hav-a-hart is an excellent brand. I can't remember but the one just for cats is a lot safer, something about it having duel doors and less of a chance of getting a leg stuck in the trap. (I thught for sure I heard that before).
Here's their website, comes with a store locator too:
http://www.havahart.com/

I have found the cheapest places are farm & tractor type supply stores. I'm not sure if they have websites as I don't recall any of them being nationwide, usually just local stores.