Strangely enough - our Harry did exactly the same thing just as he was turning 1 year old, he worked himself up into such a state every time, scratching like crazy on it's floor and destroying everything in it....
So we did the same as you're trying....he was totally house-trained and was past the chewing stage, so we gave him the run of the house (we were so, so anxious about doing that, but we made the periods of time gradually longer) and, thank goodness, we've never ever had a problem....
I truly hope things continue to work well for you...and that's she's still being a good little girl!