Old kitty, new kitty

Question
I have a cat that is approximately 11-12 years old. (Rescued during Hurricane Charley, age approximated by vet.) She has been the perfect kitty and never given us any type of problem. Recently we took in a very young kitty, rescuing her from abuse by our neighbor's grandson (with my neighbor's permission, we took her). Now our older cat is doing her business anywhere she pleases! She's never done this before. Even sorted laundry, waiting to be washed, is in danger of her using it for her bathroom. The floor in my son's bedroom is especially in danger because that's where the litter box used to be. But she has gone in the living room, laundry room, and in his room, but on the floor. The litter box is only a few feet away from it's original place, just at the back of the hallway, outside of his room.  She even ruined a recliner that was in his room. :-(  Thinking of taking the newer kitty to someone who can care for her. She is feisty and likes to tackle my old kitty. They do not get along at all.  
I would appreciate any advice.

Answer
If you can find a loving home for the new kitty, I think that would really be the best. Until you find a home, put down 3 litter boxes. The new kitty may be, even playfully, scaring the older cat away from the litter boxes. You could also separate the cats into different parts of the house.

Also, for now, pick up all the rugs, cover furniture with plastic and keep doors closed. Give your older cat a lot of extra loving, never chastise her and play a lot with the new cat in a separate area.

If you decide to keep the new cat, please call an animal communicator who can help you figure out what would make your older cat the happiest.

There are some great flower essences from Spirit Essences that address new cats, multiple cats, etc. Read the list on their web site to see if one or more seem to fit. They are totally safe, so it is fine to experiment.

and thanks so much for rescuing the kitty, even though it turned into a nightmare.