Is there anyway to get rid of that orange skin tone that fake tanners produce and give more of a brown appearance?
some type of gel on the lights perhaps?
Lighting wise you may be handcuffed. If possible, tweak the color temp in the camera to come to more of a realistic skin tone. There would be a risk of wacking everything else though.
Depending on the situation, you could add some CTO gel to your lights before white balancing. It might shift you toward blue enough to make the person look human. You'll have to test it first, of course.
This is just a stab in the dark, honestly.
EDIT: The more I think about it, the more I'd try to minimize the orange in post.
Hmmm, get a picture of the person under "normal" lighting and see what you can do in post. Even if that doesn't work you should have an idea what colors you need to add/remove on-set to get the best result.
A program like After Effects can pick out reds and oranges and dial them anywhere you'd like them to go. Just don't put the person on an orange/red set.
apply 3 Way Color Corrector or Color Corrector in FCP selectively to her skin tone using the dropper and adjust away. More than likely you will need to desaturate more than anything else, though you can adjust hue and other levels as wel. If there is another actor in the shot, or she's standing in front of a wood wall or something - in other words it adversely affects the rest of the shot, composite the treated shot and the untreated shot together.