Let the critique begin!
I like on what you color the eyes and her hair because it gives me an impact and also this will lead to favorites without enlarging it. The background makes your work more original even though you just simply do your coloring practice.
For originality, since that you colored the line art. A 3.5 stars is enough and crediting the source of your coloring piece is still good.
I thought that you drew this but then its only a colored line art. Still, your improving from time to time. I think you should draw more often and start with a sketch.