Sorry to hear about that. Must be gutted.
My mum and myself once took my brothers VERY expensive Rickenbacker home for him form a gig. We left it in the back of the cab, and the cabbie bought it back about 30 mins later.....we have not told him ! Cabbie got a nice tip though.
My brothers other guitar was not so lucky- he also left it in the back of a cab (this really isn't common, just...). Anyway, the cabbie didn't return it, so I posted a few ads up the local classifieds, looking for a guitar just like his. He had scratched his name in the head so it would have been easy to spot. I got a few calls, but none where his. It's a good way to get them to come to you.
If I ever caught someone stealing my stuff....I'd steal their ability to see/walk/talk. Their choice. Thieves are pretty low on the ladder to me.
Hope you get her back!