This PC culture is going to kill us. IMO it is only racist to people that are easily offended or looking for a reason to be offended. It was not done in a insulting way and in fact it appears to be done in just the opposite. She is a fan of the character.
Or maybe it's offensive because it's a racist depiction. The way she has done the cosplay is in bad taste. Is she racist for this? I don't think so. But she's been a jerk for not accepting her fuck up.