Duela Dent had many names across the history.She was the Catgirl before taking the identity of Scarecrone,Card queen or becoming the new Harlequin.But most of you know her as the princess of the sewers...THE JOKER'S DAUGHTER.
The Joker's daughter,even if representing a villain at first,became a valuable part of the Teen Titans.But what convinced her to make this radical change?That must be,of course,the role she played as a Suicide Squad member.
Now,the movie's cast is already set but there is still time for a surprise.Even if she's not such a major character it would be interesting to see her becoming a part of the DC Cinematic Universe.That will,of course,help her grow.Nothing has been yet confirmed but it's an interesting theory to think about.
Let's not forget that Duela Dent has also taken the identies of The Riddler's daughter and The Penguin's daughter.She also tried to catch Catwoman's attention by turning into Catgirl,later on trying to become a part of Scarecrow's gang as Scarecrone.What I'm trying to say here is that she has connections with many other iconic villains than the Joker,so she might be involved in any other possible way.
Also,let's not forget the rivality between The Joker's daughter and Harley Quinn.As Harley will appear in the movie,played by Margot Robbie,it wouldn't be a bad idea to have some cat fight.If the Things will be as Twisted as in the animated movie,maybe Harley would switch sides and they will engage into a fight for the one and only Joker(Wich is kinda confusing due to the fact that one of them is his daughter.Dang it,DC!This was a GoT thing!).
The animated movie "Assault on Arkham",featuring the suicide squad was a movie that I personally enjoyed extremelly much.Because of that,I was just mad when I found out that such cool characters as Killer Frost and King Shark were left behind.Of course DC tried to replace them with other badass characters like Enchantress or Rick Flag but there are still many speculations that other villains like The Tattoo Man or Black Manta are yet to be introduced so...why not Duela?