I think the fleshy colours used here are spectacular and the skin tone as well as the painting technique reminds me to that of Lucien Freud. I can barely fault the skin tones as I really do think they are well done, apart from possibly losing some clarity on her right hand shoulder with the use of grey and green colours.
The background is also done extremely well, I think you have successfully managed to created the flowing motion down the painting , especially with the large grey stripe running straight through the centre of the piece, which you don't necessarily pick up on straight away, but it sub-consciously orchestrates the dripping feeling. I especially like how you have managed to keep the sense of tile work on the background with a few horizontal lines, keeping the background from going full blown abstract by a small margin works well.
The only two small areas which i seem to have any particular issue with, are firstly the top right hand corner; I feel the curvature of the paint, as well as the shading around it, makes it stand out a bit too much in the background and as its motion and flow doesn't seem to match that of the rest of the background i find it slightly eye catching.
Secondly the large white section running down the girl's face; although i love the colours used and think that putting it there works very well in the piece, my eye keeps on being drawn the what appears to be the bottom of the ear, as once again the paint strokes are circular and don't match the flow of the piece. This lump of ear seems to stick out and looks a bit too big proportionally.
Nonetheless, ignoring my two minute issues I absolutely love this piece of work and think that you're overall use of colours and paint strokes has so much potential.
I agree, the shower curtain is a good prop, for lack of a better word. What about using other semi-transparent materials, or a shower curtain with some sort of print or pattern on it (might be worth going and seeing what's available). also, I imagine you might do something really wonderful with hanging beads. Just some thoughts. I like this piece.
Looks really good, not sure what there is to critique though, especially when we don't have reference to relate it to. That'd be a better teacher than us anyway, viewers could only comment on things like enhancing the mood, and smoothing things out.