I also remember a similar scene from the BTAS episode "Over the Edge". Most of the ep was a Scarecrow-induced nightmare as Batgirl imagined that her own death in the line of duty would result in Jim Gordon declaring all-out war on Batman. At the end of the ep, she decided to tell her dad the truth about her being Batgirl. Gordon stopped her, saying, "You're a grown woman and I don't have to know everything. And in this case I can't know. But I want you to know that I'm proud of you. All of you."