She should also see a vet to rule out a urinary tract infection. Clean the
area with an exzyme cleaner.
Gail

"Simple Solution" Cat Spray & Urine / Stain & Odor Remover

http://www.bramton.com/

This solution works great. I use it to clean up the litter box and the
odd accident here and there that does happen.

I have only very limited experience with this. But for what it's worth:

My little cat was ill recently and had a few accidents. Like you, I was worried
he'd pick up on the scent and repeat relieveing himself in a certain spot. I
switched from some ordinary carpet stain etc. removers to a product called "Kids
'n' Pets." It's advertised as a "professional strength carpet cleaner, stain
remover, odor remover and laundry pre-wash." It has a smell like bubble gum that
is not overwhelming and goes away quickly. Sometimes I had to repeat the
application, but that's per the directions on the bottle. I'm on my second
bottle because I found it so effective. (Now it's relegated for the rare times
my cat upchucks. Bugs, I figure.) It's $4-$5 for a big, 32 oz. bottle. Wal-Mart,
for one, has it. I like my house clean and not smelling like cat fluids, so this
may be something to recommend this product, too.

To reinforce your litter box configuration overhaul: I recall that it's really
important to keep the cat's litter box cleaned out, too. Sometimes not doing so
may deter the cat from using his/her box.