She-Hulk, while exaggerated on the va-va-va-voom side of things, is still human enough so as not to need a CGI model. I think the better way to go would be to "Lord of the Rings" it, and make a normal person appear to be 7-8 feet tall instead. While they're at it, I think digitally coloring her green would probably yield better results than make-up, as it would allow for some more artistic touches (such as blushing, going pale, etc.)