Behavior Issue ... Shes eating my COUCH !!

Question
I have a soon to be 10 month old female great Dane. We have an active house. Myself, my two kids (8 and 6) and another smaller dog (cocker spaniel mix) I did not crate train her, she was doing well in the house while we were gone from home (work cues ) Than one day she decided that my couch was her new chew toy. Recently, I re-established the boundaries by crate training her and she took to it rather well. I use positive verbal cues to praise her (and her buddy) of when they do good and reward well when they do good. However, now she's doing it when I'm home. The other night I went to bed and I caught her out in the living room playing with the couch cushion like it was a throw toy.
She gets tons of attention, sleeps with me at night, chew toys so I'm not understanding this "change" The only time she gets put in the crate is when we leave for work.

Any advice or help would be great. Thank you for your time !!

Answer
Try getting her more exercise and more appropriate toys to chew on.It sounds like she's bored and wants to chew to release that extra energy and she's just using your couch because it's handy.She needs to have the couch replaced with something appropriate to chew on.Interrupt her when she goes for the couch and when she stops praise her and replace the couch with something else to chew on.Bitter Apple Spray can also help with unwanted chewing.