Lovely colour on the tree and the accents on the sky. However, the ground seems somewhat flat, with little depth. This may be because most of the hatching detail of the grass was in the back of the area rather than the foreground. I normally detail the foreground and then fade towards the back. I'd also add most of the grass colour in the foreground and wash out towards the background.
The composition feels odd. I think if there had been more modelling of clouds to the right of the image it would balance, but the sky becomes very indistinct here.
I thought the angel gets a little lost beneath the tree, with one wing almost disappearing. Also the pose os unclear. Is she hugging her knees or does she just have an enormous cleavage? A problem is that with so much of the line work being quite delicate, the angel seems crudely outlined. A lighter hand may have made this work.