NICE JOB SO FAR!
Great work

The ever-elusive eyelash...

I think you are going about it the right way, by using control curves, but have you tried fur?

I've heard good things when using fur for short & curlys (hehe..., eyelashes, peachfuzz, etc.

The good thing about fur is the shadowing, the bad thing I've heard, is that it takes longer to render.

The bad thing about PFX is the shadowing, but the good thing is that it is easier to control, and renders SUPA-FAST

...so it is up to you, as to which detail-route you wish to take for this difficult effect.

Textures, with a subtle hint of PFX and/or Fur would go FAR to adding to realism for a believable brow.

Good luck!