Can a women apply tattos on her aerola?

Yes. Since the skin in question is rougher than normal areas of skin, sometimes the ink will have a bit of trouble going in well on the first pass, so it may have to be gone over more times than you normally would have to, but the site as well as the nipple itself can be tattooed. The ink may or may not fall out in spots during the healing time which can result in the color being spotty, but this is not always the case. Naturally this is a very painful spot to get tattooed as well, so this is something that must be taken into account before you go to get the work done.