Have you provided her with a scratching post?  You can put double sided
sticky tape on furniture - Sticky Paws is available from pet store or
stickypaws.com - she'll touch it and her paws will stick to it which she'll
hate.  

Kittens will do that.  Just walk away when she does it to show her you won't
tolerate it.  Don't play with her when she does it or she'll think that is
the way to get you to play with her.  Hopefully she'll grow out of it.

Anna

she won't "out grow it" if you do not provide something appropriate for her
to scratch on.  Cats routinely use something big and stable to claw, to
remove the sheaths on their claws and to stretch.  They also scent the item
to mark their territory.  People often give tiny posts, and the cats can't
use those as they need to. Give her something big and stable, a scratching
post at least as tall as your hip. the reason they use furniture is because
it doesn't move.

They say that you're not supposed to hit cats, but at one point I decided
that I had to defend myself.  It worked.  She was smart enough to figure
that one out.  Keeping her claws trimmed also helped.