You need to figure out a way for her to be punished when you are not home. Maybe a scat mat or the like.

I do not reccomend that you use the dogs name when punishing the dog, just tell her a firm NO, I presonally don't even see a need to scruff her or look her in the eyes. Just tell her OFF (not down, unless you don't use the word down when you want her to lay down).

What she has learned is that it is not ok to get up there when you are around, but when she's alone there is no punishment. What a smart girl. Bad but smart. lol

Does she have a bed of her own?