Thanks so much for your replies!
She may have bumped her head when I put her in the cage. They were all flipping out a little bit. I thought of the broken leg thing, too, but I don't think it's that. I picked her up and she gripped my fingers with her feet, and her legs didn't seem dead as they often do with a break. I'll keep an eye on her, and if she doesn't improve I'll bring her by the vet (I'm fortunate to have a great avian vet right in the neighborhood).
Thanks so much again for advising me, I really appreciate it and so do my new little pals.