The 30-year-old actress was already confirmed to be a part of the much-anticipated movies but her role was undisclosed.
Barbara is the current Batgirl who works alongside Batman and the first Robin in the comics, reported Aceshowbiz.
She is also a daughter of Commissioner James Gordon, who has been rumored to be dead in the upcoming movie.
Barbara adapted alter ego Oracle and helped the Caped Crusader and other heroes using a massive world-wide communications and espionage network, after she was paralysed by the Joker in Alan Moore's "The Killing Joke" graphic novel.
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It was her recently-dyed red hair which sparked the speculation that she would play Kelley.
When the Comic-Con trailer surfaced, fans immediately noticed that it was not Malone, who played Robin. It can be seen from Robin's suit in the trailer, which resembles man's body size. So, Robin is possibly a young man played by director Zack Snyder's son Eli Snyder.
Even if the rumour is true, it is still unclear whether Malone will play Batgirl or Oracle in the upcoming movie.
Directed by Zack, the movie will arrive in US theatres on March 25, 2016.