Back when they did the second phase of the Batman series, they had an episode called Growning Pains, where Robin meets a girl who is being chased by a thug. It is revealed that the thug is Clayface, and that the girl; Annie was created by him, which makes her a part of him or even his daughter.
This is Annie:
To save Robin, she becomes one with Clayface again, but this angers Robin and demands her back, but 'Face says he can't. Later when Clayface is captured, Robin believes he should be charged with murder.
Then Batman Beyond came, and with it; it sealed the future of the DCAU and a return of Annie. JLU appeared but we already knew how things will end up.
And so Annie is forever lost, she is my all time favorite DCAU character.
We have the comics to see your our characters longer.....
Even as the Protector of the Universe, you sometimes show ignorance befitting a mortal Milo Ventro. And that is perhaps the best of you
Poor Annie... Robin was hurting bad.