Margot Robbie explained how difficult it was to make “Birds of Prey” a reality. According to Gizmodo, Robbie said it took her five years of a lot of resistance to get the film done. Robbie said she noticed a large fan base for her character Harley during Comic-Con. The actress then researched more about female DC characters and wanted to reveal them to people. Robbie said the planning began before “Wonder Woman” and they had to spend a lot of time developing the material.