This is really nice. Needs to be said! really nice! The wolves look amazing, and the composition workes perfectly.
But if you want some avdanced critique, this is my two cents:
First thing I notice, although it's just a detail. The forearm holding the spear looks quite flat in the middle.. I'd suggest using some subtle flesh tones there, to avoid that effect.
Second: after looking at this picture for a while (cause I really like it, did I mention that?
), I come to notice her right leg... and, boy, it seems to be in an awefully uncomfortable position.. o.o All the time I thought it just didn't show, you know, like it was stretched in the back, like she was preparing to run after a prey. I think it would work better that way.
And lastly... the tip of the spear. It looks too BIG and heavy for a spear... I seriously doubt she could hold it like that in the air. You should either make it smaller, or make it touching the ground. I'd go with the first one.
Well, that's all I can think of..
Keep it up, you're doing a fantastic job (I mean on this and all your recent works