When it comes to comic-cons and cosplay there are no set rules as to how you may portray a character. Some people come to the cons in store bought costumes; others meticulously hand craft theirs (they are the ones who often win the costume contests) judges love that. And there is some gender switching. Women can be a male character feminized somewhat and men can be a female character. Also, there are some iconic characters that in their lifetime have seen many incarnations and costume changes…even Superman has had his uniform changed a few times in the movies.
Here we have a variety of Harley Quinns including a male Harley (first time I’ve seen that) and a couple of Scarlet Witches. Currently I have a Harley Quinn costume in the works; need to get a certain type of corset and a baseball bat 🙂