Looks great Mr. Small!
Love what you have so far!
And yes, Ripley is a bunch of simple retouches. Hair and eyes, mouth color and a general look of "lack of makeup". That's it.
But, several members have repainted their's to great effect, with little more than hair, lip and eye recoloring. Small here has done a bit more. Great work bro!
Jedi Mike, your's looks really good, but be careful with the lighter browns. She did have brown hair, but, to catch that light coming through it trick, you might try painting the tips of those sharp areas, gathered hair tips, your rich brown, and only here or there, otherwise, it makes her hair look frosted.
And, it depends on the part of the movie of course.
Later on, when she's going after Newt, it's all wet and totally dark. Almost black.
But cool stuff! I can't get over how many different ways there are to paint her!