Your frog may be dead, but there's not enough info here to tell. As far as I'm aware a frog won't start to aestivate like that overnight right after eating (I don't aestivate mine so someone with experience doing that may have more info). Can you post a picture of the frog?

When you say 'rock hard' do you mean her skin was tight or actually hard? Did it seem like there was a layer of hard mucous covering the skin?

Also, answer the questions from this link so we can get a better idea of what may have caused that.
http://www.frogforum.net/pacman-frog...enclosure.html