Does she have a soft cushion of her own to lay on? Carpet just isn't enough and some dog beds are quite lacking too. When we go over to my Mom's she has a beanbag chair that is Victor's and he knows that is his place. With his knobby leg bones, to lay on the floor would be painful for him, he flops around and cannot get comfortable, not to mention that at this time of the year the floor gets pretty chilly.
They do have scat mats..my friend Kelly uses hers to keep dogs off of what she doen'st want them on, I just show them their place, and they learn to go there instead. Some people use mousetraps turned upside down, but that seems too risky to me.
I think if u give her a comfortable spot and let her know persistantly that she is to be there and not the couch she will stop jumping up. A squirt gun works great too, or some rocks in a can that you shake, what ever gets her attention.