At first I would not think this as a digital piece. And after realizing that it wasn't my second reaction was that you had used a few filters to give this a feel of a painted canvas piece, but then I realized the error of that those thoughts as well. I think I may need to look in to this Artrage a little more.
Anyway moving on.
As mentioned with the last piece I reviewed for you, I like your lighting, you seem to have a nice grasp on your lighting. You have a couple areas that could use some shadow play, like the dome of the windmill and its side, but you still do a good job over all.
One thing you need to work on is your form a little. The clouds reveal this most of everything. I think you could get a much more impacting sky with a little more form. Work some highlights in to some of your darker clouds to give them some more dynamic depth and to really push up your lighting skills. Work to your strengths, right?
Colors are nice and vibrant, This entire piece has a nice up beat feel.
I think you could have added a little more texture over all though. you have some in the grass and mill, but I think you could have gone a little further, not much, but just a little.
One thing I do need to mention is composition. Your main focus, the mill, is right smack dab in the middle of the frame. You usually want to avoid this. Try to follow the Rule Of Thirds: http://www.google.com/search?hl=en&q=Rule%20Of%20Thirds
Following theis will help your composition a lot. I think if you had gone fora wider shot you could have had more room to make clouds and lead the eye around a little before settling on the subject of the piece.
On top of everything, I think your mother would like this gift. you put in some nice effort, and had a couple of strong skills to show her.