I think that you had a different way at looking at a Geisha I like the way I feel you captured the natural beauty of a Geisha. Very well done! I like your choice of color as I think of a geisha the colors you use give the effect that a gaisha's makeup would provide should you have provided makeup for her. The flesh tones are amazingly beautiful. The lips are perfect and I like how you added the sort of glow to her eyes. It is almost as if she is walking outside and is being hit by a gentile breeze.
This is beautiful though not exactly a traditional geisha. The name geisha brings to mind a heavily made up woman dressed elaborately for a party but I could see this being during the day time.
The colors blend beautifully and you did an excellent job of picking a nice contrasting background color to match her kimono.
The face is absolutely perfect, the proportions look right to me and the eyes are draw you up. Her hand though seems to just appear out of no where and the arm attached to it just looks a little awkward. I think you were trying to go with a sweeping motion but perhaps define the sleeve just a but more so that it doesn't seem as though her arm was just plunged out of a gap in space or not apart of her body.
I'm assuming the dark curve in the lower right hand corner is her hair. It curving to the right while her dress is blowing to the left is just kind of off if you meant this to be realistic. If you brought her other hand into the picture and hard it raised so that it looked like she had just flipped her hair over her shoulder even that would make more sense than things just flying in two separate directions.
Overall it's a nice concept and this is something wonderful to build off of.