I think packen is entirely correct. hitting is punishing. since they crave being active and the center of attention as puppies, putting her in her kennel immediately after saying 'NO' when she chews should be effective. if she has an option to chew on OK stuff like toys and not get put in time-out, or the sofa and immediately have to spend some time alone she should learn.
the greatest challenge will be you rounding up a puppy every time she chews, but keep at it regularly and know she'll catch on one day and you'll never have to do it again.
Tiger A.K.A Clown Town- 12/19/13