The perspective is a little off between the stairs and the banister. The stairs get very far away and very narrow, while the banister stays the same width all the way up the stairs. Most one-story sets of stairs go up 14-16 steps, if that helps. I think if you stopped the stairs at her midsection it might look more natural, and that would remove any illusion that she is laying flat on the steps (mentioned by Shizzle). Also seems to have a lot of dead space at the bottom of the picture. (No pun intended.)
Thanks for the awesome crits Manupix. I wish I had more time this week to play around with this. The simulated transparency was my focus on this one. I see from your references how the window could really be played up. Nice examples.
EDIT: Anyone notice the demon in the mirror? 
Nice one =)
Agree with Shizzle and Gecimen. She could have some transparency gradient (hand made of course ;)
The light from the window might flare around more or less. If more, it could even mingle with the ghost.
The lighting on the left side wall should also decrease toward the foreground.
The absence of a banister on the landing is dangerous!
Watch that banding on the handrail, too.
Good one, only a little too obvious. If you make her look more transparent her misshape will disturb the eye less.
Looks good, but she looks like she is laying down on the stairs due to how her outline perfectly fits the perspective of the stairs. Maybe move her up about five steps so it breaks this illusion.
awesomeeeeeeeeeeeeeee eeeeeeeeeeeeeee eeeeeeeeeeeeeeeeeeeeeee !!!!!!!!!!1 e-e
Reminds me a lot of Annihilator's Alice In Hell cover, like maintrix already said. Nice drawing!