The Batman: Every Character Confirmed So Far (And 5 Rumoured Ones)
10. Batgirl (Rumoured)

In fairness, there were rumours that Batgirl would be appearing in The Batman way before any casting announcements or character confirmations. There has been a solo movie based around Barbara Gordon's alter ego in the works at DC for some time now, with Joss Whedon attached at one stage, though has since dropped out.
Despite The Batman not connecting to the current DCEU as we know it, there is nothing to stop it from tying to the upcoming Batgirl project. Though Karen Gillan has recently revealed she'd love to play the character, some fans are now seemingly getting behind the idea that Bella Reál will be Matt Reeves' version of the character.
Whether Bella is the true name of the new Batgirl, or an alias for Barbara Gordon in the same style as Talia al Ghul in the Dark Knight Rises, there is certainly a possibility of Reeves and Warner Bros bending the truth slightly with their announcement. Either way, many on the internet can definitely see Jayme Lawson playing Jim Gordon's daughter, who has in fact run for political office in the comics before.