My Jilly was a scratcher/digger. She dug a hole in my very expensive duvet in only a couple of weeks and taught me a lesson. Digging/scratching was her passion and she was a chewer/destroyer of her toys. I trashed the duvet, changed to an inexpensive one, put tinfoil in places around on the bed and for some reason, this stopped her destructive scratching/digging. Why wouldn't she destroy that cheap old thing and not the expensive, ultra soft one????? Anyway, from that time on she stopped her hard scratching for some reason, maybe because the other duvets and bedspreads after that weren't as enticing or something. I still would occas. place some squares of tinfoil on the bed from time to time just here and there for years to"remind" her but still don't really know why she stopped.
I hope you can use tinfoil or a series of cardboard boxes, poster board or something placed atop the couch when you aren't home to prevent further damage. Of course when home, you can verbally stop her when you see her start in. I'm sure sorry she did that - I know how dismaying it is to have expensive things totally destroyed by our sweet little "dears"!