Why not???? I have one declawed kitty (done by previous owner) and one with claws. They don't like each other very much so they stay out of each other's way. There's been no problems at all. Just remember to think about the purrsonalities of your present cats and will they tolerate another kitty? At the same time check out the shelter kitty's background. Then again, I guess you know all this already.

Good luck and I'm sure she will be very grateful to find a furrever home.