Impressive ! Though I think you could have cropped the composition a bit. There are a lot of empty spaces on each side, I would probably have done something strongly narrower, like this [link]
Apart from that, I really like the misty mood of your colour scheme, it's warm and pale, rather different from the usual schemes you use in your landscapes. I wouldn't have thought you would be as good in portrait painting than in landscape painting, but hey, seems you can paint anything o_o !
I don't know if she looks like the real person, but she's very lively, dreamy, and pretty. Like your loose brushwork too ^^