I assume the girl is kneeling? It reads more like a really short person.
The wolf also looks more like a horse with those long legs and the size of the girl. Maybe the neck is a bit long, I'm by far no expert on wolf anatomy though.
Edit: I just saw the reference Image, the long legs do look correct now, but as you said, it's a bit heavy and not as slender as the reference.
I do like the colors, but the grass might be a bit too saturated when it's that dark.
Also, consider making the image more rectangular to give it more of a direction.