I know one is Talia's kid from
Son of the Demon, which Grant Morrison brought back. Who was the other one ( or nearly the other one)? Do you mean the revelation that Terry McGinnis is Batman's son on JLU?
I really don't mid the idea of Batman and Superman having kids...they are modern myths in my book, and the father/son dynamic and conflict has been a big part of mythology forever ( Like Zeus and Hercules, or King Arthur and Mordred ) As the DC characters are more "larger than life" than the Marvel ones, to me it fits. Plus...I just don't buy that Supes and Bats are "forever 29" anymore...especially Batman, who has raised 3 wards, the oldest who is at least 25 now. I see Batman as early 40's ( And Superman too ) Nowadays, 40 is not what it used to be. Brad Pitt is in his early 40's, as are people like George Clooney. I just don't think of it as old anymore. But maybe that's cuz I'm 32 now.

In any event, old enough to be fathers for sure.