It was mentioned by Patty that Wigg will have prosthetics enhanced by CGI. And if you go to the IMDb page the prosthetic makeup artists are Jo Grover and Anna Kießer. Jo did work on Beast in X-men: First Class ....but I really hope she doesn't look like Beast did in that movie, it wasn't good. I don't think she will.
But yeah, definitely going for more than just a woman in a cat suit.