It looks great, Especially so for a second picture, It would still look terrific if it was your twenty-second.
It also looks like you got some foreign objects in your layers while you were drawing (A common incident with Shi-painter).
Her hair could be wanting a few antialiased... Gosh darnit, whadd'ya use? A pen, thats right, You might Pen some stray strands of hair on her face and at the tips, make it a bit more jagged-like.
I would recommend the Soft Eraser (Eraser2) around the top to get rid of those hard angles and such.

To get rid of those most unaesthetic blotchy things on the neck and face, some skin-coloured patching with the Watercolour (Water) brush and a tiny bit of Blur (Grad)... Ooh, and blur the lips up a bit, it loks like you used a Sharpen brush on them too many times.
Don't uver use the blur tool though, it makes it baadd.

That's all just friendly advice, it's not required that you do anything I said, this is still great. ^_^
I also love those straps on her shoulders; they really look ribbed.