backlit (window light only)

...such as lack of critical sharpness on the subject's face (70mmequivalent hand-held @ 1/30s and f/5.0, ISO 400) and blown highlightsin the hair (could have controlled that better in post-production),what do you think about this portrait?

It is not posed, and was shot in available light only, which happenedto be coming from a window behind the subject; a reflector to bouncesome back would have done wonders...

I find the blow highlights in the hair not a problem.

The photo needs just some more contrast in the face.

 

For some reason this photo displays "flatter" in my Firefox browser than in PS -- have double-checked that I converted it to the sRGB colour space, so not sure why -- while Safari displays it properly.  Maybe for the same reason it looks insufficiently contrasty on your monitor too?  Anyway, I gave it a wee midtone contrast boost; here's the result: any better?

Yes it's much better.