I will add my advice to the other excellent comments here.
Please do not declaw unless the only option is giving the cat back to the shelter. Sticky tape, cat repellent sprays, all these things can help. Talk to the vet for other options.
We rescued an adult cat from the roof of a supermarket many years ago. She was our first cat ever, and she shredded our furniture. No big deal, we thought, we'll get her declawed. Only after the fact did we discover that declawing is like cutting off your fingers at the first knuckle.
Outside, a declawed cat is totally defenseless, and will not live to see out the year. Please, try using tape, repellent, providing sisal scratching posts next to her favorate scratching locations (put a couple of cat treats on the base of it). Lots of stuffed mice and cat toys to alleviate boredome.
Never, ever hit your cat... not its paws, not its rump... just don't. The cat will become fearful and hand-shy, and may end up being a biter/fighter every time you go to pet or touch it. Cats are fragile creatures, and they know it. Please. Gentle love will gain your cat's trust, and once it realizes that the sisal posts are much better for scraping the dead husks off their claws that flimsy furniture (which you have protected with tape), there will not be a problem.
Let us know how it goes.