For a first head, I think you've achieved alot of the important parts pretty well, I've gained a real appreciation for how hard character modeling can really be... its not nearly as easy as I once thought. As you noted, this chick definitely has some issues, so let me point out possible spots to fix up (in the spirit of being helpful). You may alreayd now all this so bear with me :p
Most of the poroportional issues I see are with respect to the eye size. The nose seems like it could be a tad longer and definitely wider. Also the wings on the sides of the nose should be taller. She could have a bit more pronouced brow close to the nasal bridge and should have that 'puff' of fat above the eye at the outer part. Also the jaw could use some widening and the cheeks should be brought more forward. There's a large bump at the center of her head between the eyebrows -- should be almost flat in there.
If you don't already have this link, check out
http://www.fineart.sk/ cause its the perfect resource for example pics... its a gold mine
Here's a pic that I thought you might find useful, which I hadn't seen on fineart.sk. I scanned it out of a book I have. You can proportion your head based on 'eye widths' (an unusual unit of length
) Please download it as soon as you can so I can delete it from my drive space.
After you get your head set up, you can then use your ladys head as another base unit of length for getting her body set up (if you intend to go that far), like ofr instance:
click the pic
