Okay, I tried combining everyone's suggestions: Skin 6, opening the space between brows and eyes, thinning the lips... and here's where I've ended up. I feel like I've overlooked something, and the strength of the original's face is definitely lacking. Something seems off with proportion or balance, too, but I can't figure it out. I tried some tattoo layers for lip color from a couple of places but it didn't fit. It looks like the upper half of the lip is drawn directly onto the skin and the layer only goes as far as the shape or something.
What do you think and where should I go from here? Thanks for your help!