On the off chance she's flying British Airways, I can tell you there is no charge for a bike, but it must be in a bike bag ($30 from Nashbar) or a bike specific case (think of more expensive hardshell cases). I'm flying in early September -so I hope the policies won't change on me!!!
I've heard that some other international airlines charge, some not..... If she's not a really big cycling enthusiast I'd think buying a bike over there would be easier. Having said that, it might be even cheaper to get a reasonable bike off craigslist here and still pay for shipping if the airline charges it, and then sell it over there at the end of her stay.