Elf in the Water with a Sunbeam

So, I drew this at a chalk art festival my home town does. I decided to draw this and it came out okay. I'm better with pencils then pastels. The elf looks okay, but the rest, the nature part, it needs work >-<. I would have finished it, even though it looks finished, I ran out of color of brown so I couldn't put more design to actually look like a tree. Could you tell there is a tree branch? If not, it's okay because I ran out of dark brown and couldn't separate the colors. If I did have more, you could tell there is a branch.
And the green that is going along the tree from the bottom to the top is grass, except the little part at the top. That's part of the tree which I wouldn've made that a darker green but ran out of that color too. *Sigh* So, there is the grass and then at the top, the green is part of the tree. Oh, and there is a waterfall in the background, really hard to tell since It's my first time drawing a real waterfall but that's why I'm not going hard on myself, it's my first time. And, behind her arm, you see a reflection of her hair in the water, just telling you so you don't get confused.
...I think I've written enough already :) Please comment!