Harley Quinn with be making her film début in Suicide Squad soon and I think its fair to say people are most excited about her character above all overs. Margot Robbie who is playing Quinn has somewhat stolen the show. 

So naturally it makes sense that she will be the lead in a new female lead DC movie. Characters that could share the screen with her could be, Batgirl, Birds of Prey, Poison Ivy (my fav), Katana and Bumblebee. 

Will be interesting to see how this develop's I will be keeping an eye out for news, especially the casting of certain characters.