Comic book characters do age, but not in the same way that you and I do.
Upon her reintroduction to Gotham, the Huntress meets Catwoman, and Catwoman immediately takes to Huntress's renegade style. So, Huntress asks, how long have you and Batman been chasing each other? I know it's only been two or three years, Catwoman replies, but it feels like seventy.
And that's how time works for comic book characters. Time isn't linear; it would be closer to say it's parallel, but even that isn't exactly correct.
As DC comic fans know, until Infinite Crisis, continuity problems in characters and story lines were explained away through the use of parallel universes. Infinite Crisis put an end to the alternate realities, but character relaunchings still occur. Thus, Huntress's origin story is entirely rewritten, for example, and her placement in the DC Universe shifts.
The writers claim the practice of starting characters over again and re-imagining their beginnings helps to keep them (both writer and character, I suppose) fresh. And as long as the essence of the character remains the same, who can complain about petty things such as chronological details?
Start your story over again from the beginning. What details do you change? How do you keep your "essence" the same?
"Desire is the very essence of man." -- Baruch Spinoza