I think she'll be killed or destroyed, but this may turn her from a "Grendel's Mother"-like Forsaken to possibly a Dragon-like entity or active seeker or revenge to tie her more closely to the Beowulf myth that inspired her name, unafraid to enter the lair of the heroes to achieve her revenge, whereas before her focus was on staying in her own lair and not risking anything besides her pets. I think that the death of her pets in the Barrow was the equivalent of slaying Grendel, her punishment was symbolically like Beowulf entering her layer and killing her and her next appearance will be with her as nothing left to lose.

We'll see in the next book, though! It would be unfortunate if she has been destroyed since IMHO her failure was not as bad as Ishamael/Moridin or Lanfear and ultimately, we do get the image that she was the Forsaken that carried out his command to unleash balefire in his service. We'll need to see how far her punishment went.