First off; wow! Looks great. I agree about the eye spacing, but understandable if it’s too late to adjust that without having to readjust your textures too. I agree with Sundialsvc4 about having her look at something specific, might help the eyes a little (I would personally try having her look at the person taking her photo).
A couple minor suggestions:
First, her overall skin has some blotchy areas or a little too much variation for my taste (lighter and darker spots). This can sometime happen due to brush strokes or the stamp/clone tool. I’d just even it out a bit, not too much though. Just a slight layer of makeup 
Another thing would be to watch the specular. It could be just the lights or texture but I’d have her skin more softer looking (probably softer lighting?). Not quite sure, try comparisons with real life portraits.
Also, the ear/s need work. They need to look more like the variation on the cheek and around the eye: with a light “baby” skin covering most of it and some more reddish tones in crease areas, etc.
I’d reduce the brow ridge between the eyes and nose a bit and have less of a defined line separating the brow and the nose. You could also try shrinking/toning back the chin a bit, see if that gives her more of a feminine look (not sure if it will).
Finally, I’d try rendering her with an HDR image as your lighting, as a test render. That can put your model in a more realistic lighting environment to show you what it more ought to look like, if she became real. Then you could use it as a reference, and create your own environment and lighting setup based off that and remove the HDRI (or just keep it, whatever)
~Regards