Is my tarantula molting, or dying?

I know that tarantulas molt on their backs, and that they look like they're dead, when molting. What I don't know is how long the actual molting phase takes place? My "Lucinda" went on her back last night sometime around 9 or 10 (as far as I know, it could have been earlier). I got up this morning hoping to see my new little spider and her old cuticle, but she's still on her back. I've been misting her cage more than usual to keep humidity up. When I mist, sometimes I'll hit her directly by mistake and one of her legs will move. I'm also worried about the two times the water has made her move. Could this slight movement have hurt the process in any way? Thanks for your answers!