Loving this so far.

Can't wait to see the wolf completed. Maybe some wolf armor?

Also, why armor, why do you have to exist?

Hm, also, I have two options:

- to leave her eyes that way (looking at something beyond the canvas) or
- to set her eyes to look straight at observer (more dramatic)

Option number two may be better since I'm sure my pal would like that. :]

the lips look duckface-y

I think you are off to a good start.

I believe it would look a bit silly to make her look at the viewer from that angle she is posing at.

Love the angular lines, love how shes actually muscular, you've thought through the concept pretty solidly and i love the rough shading style.
i do agree with bostaff on the duckface, cannot be unseen.
i think more definition is needed in the connection between the shoulder/upper arm to bicep area, maybe just extend the shoulder line over the bicep area, ive got a pretty slender build and i can see the line from my shoulder in that pose.
love that little crease inside the elbow, really good attention to detail.
also, in the same way, the anatomy on the back part of the hips/bum/thigh is pretty spot on, but still makes her look a bit frumpy in that area, correct, especially in a musclar chick, but still frumpy.
perspective on the sword looks funny, probably has to do with the little triangle at the base of the blade, makes it look bent, perspectives going one way on the handle, but the other way on the blade.
also, im sure youve noticed this, but theres a small line under the back eye, that really makes her back eye look fuuuuucked up. erase that little line and its fine though.

youve got your ideas for the background and lighting changes down, but i do think the grey wolf and snowy backdrop would look better(although the practicality of her outfit is a bit confusing in that climate), the contrast of the white/grey with her hair and eyes is effective, really helps make her face the focal point.
also, one doesnt usually associate plate armour and wolves with the forest scene, leather and a big cat suits it better (not saying always, just in this case)