Originally Posted by
mikelmcknight72
I'd set a permanent age for Clark, Bruce, Hall, Barry, etc around 38-40. Through the wonders of comic books, the more human members of the Big 7 would have had their aging slowed a bit and their vitality preserved.
When Bruce had been operating as Batman for roughly 3-5 years, he'd take on Dick as a ward. After some training, Dick would have become Robin at 12-13, Nightwing at 17-18, and he is currently around 25 (as are the rest of his generation of Titans and Barbara). Bruce would have adopted Dick before taking in Jason
Jason was with Bruce about a year before Dick became Nightwing. He'd have been adopted shortly before his death, and he is currently about 21-22. He operated as Robin for perhaps two years, and was believed dead for several years before Under the Red Hood.
Tim would be 17-18, as would his YJ compatriots. He became Robin around 13. Cassandra Cain is older than Tim but younger than Bruce. Spoiler is Tim's age. At some point after both his parents deaths, Bruce adopts him. Cassandra was adopted most recently.
Damien would be about 13 and has been Robin for about a year. For a while, he and Tim are both active as very different Robins. Jon would be at most one year older than Damien. This timeline affords the necessary time for natural conception and aging for Damien.
Exact ages would not be shown in panel for any character, and birthdays would NOT be shown....EVER. The above information would inform how characters are written. It isn't a perfect timeline, but it is close enough that I think all but the most stringent continuity buffs could accept it.