Definitely watch her for more signs of an RI because that could be a sign of it, but since you say that you just picked her up I'd bet that it's just because she's stressed. Mine used to do that when I had him out for long periods of time, and it kind of sounds like a cricket chirping.

Let her adjust to her new home, and if you don't see any signs of RI, handle her a bit and see if it goes away as she gets more used to you.