ariana is done in zbrush maya skin is mixed of xyz maps and zbrush dismap, skin pores done in mari ,hair is xgen ,rendered in arnold in maya and i did some over paint in photoshop.
its inspired from one of the old books from stella mackie drawings which were published from Walter T foster publications.(( for rather more simple look i kept detailes almost off in the portrait head shots only))
Ariana short video in zbrush and maya and substance painter:
more on my artstaion: