Couple of ideas to pass along:

1. have plenty of scratching posts. Tall ones preferred, lol.

2. Periodically, rub catnip on the posts, lets kitty know that is HER place.

3. At the same time you do the catnip thing, make a spray bottle of white vinegar and water, equal parts. Spray that on the furniture. Dilute enough that humans don't smell it, sharp enough that the cat does.

4. Go to a craft store, buy some double sided sticky tape and put that down the sides of the furniture. Be sure to do BOTH sides at corners. Cats don't like having their nails "sticky."

I've done all of these at one time or another. Sometimes, they even worked for me!