Sounds like she's quite desperate, enough so to realize she has nothing to lose by asking.
I agree, I wouldn't loan her the money (unless you felt you could afford the risk of never seeing it again and she tells you exactly what it's for - of course, if you co-signed a loan for her, you'd probably learn what it's for). But I wouldn't take offense at her asking, since she probably isn't trying to be an opportunist.
I'd be shocked, too, though.