Im no professional but i would like to make a suggestion. You should put a lot of detail on the eyes, you went with something simple which is great. But as i view this peace her eyes grab my attention she looks pure and innocent. I believe if you added more detail to them it would make the image pop more and give it that personal connection with the viewer.
Your choice in colour is great, her pale skin makes great contrast with her hair and the reflection on the water adds realism. Your blur on the far upper right was too big of a jump from the middle. Maybe a water effect would have been a better choice. All in all its a beautiful peace, please don't take my critique too harshly.
There is no denying the skill behind this picture. The attention to detail is prominent in the hair. Though, two points I would like to raise are how the hand seems a little alien in comparision to the girl and how the top left corner doesn't look like a part of the picture. I understand that you have used a reference and that is the reason for the abrupt change in the background. But keeping in mind that the original was a photograph and this a traditional artwork, it is impressive. On the whole it is very close to realism and the only scope of improvement would be adding a little more detail to the aforementioned background (the sudden change of focus is a little unnatural). This picture gives more insight on the artist's skills than the general concept, since it is the artist's take on a photograph, which may not be the intention. Whatever the case may be, there is no denying how pleasing it is on the eyes.