Awesome!
The shine on the lips, and the smoothness of the skin are amazing, and the hair is also very effective!
The biggest issue I would have, is the mouth. The lips and teeth look like they are glued on the face....almost like they are covering up the real mouth, or something. They look like they belong to the rest of the face, but there's something about how they're connected to the face that looks funky. Some different kinds of work all around the edges of the lips/teeth, I think could help a lot. Like on the corners of the mouth, do you see the weird kind of folds -- on the lady's right mouth corners (our left), where one would think it would be under shadow, there's a bright patch. And on the lady's left (our right) which should be fully lighted, are some dark smudges. I'm not sure exactly how to do it, but there probably should be some little shadows just under the bottom of the bottom lip. There's a little already there. And I'm not sure, but it may be, once the corner folds are fixed, the top and bottom edges might work very well. Sometimes it's hard to make a suggestion without having a file to play with
The 2nd biggest issue I see, the lady's left (our right) eyebrow seems to be missing altogether. There are a number of other areas where I might comment, but since it's a work in progress, you may well plan to fix them already. So I wouldn't want to sound too picky, at this stage. Plus, I'm so late for dinner already! I'd be glad to mention everything later, if you like, just let me know

Edit
PS - Ragnar, or anyone wanting more like this, including funny little pig, for inspiration, search out posts by Snel, another excellent photoralism Inkscape artist!
