Actually, most of the original JSA are dead. There are only four of the originals still around and these are through plausible (in DC/comicbook terms) means.
Green Lantern. Merged with the Starheart. No longer human.
Flash. Kept younger than he should be by the speed force.
Hawkman. Reincarnates. You kill him, he's just reborn.
Wildcat. Was given "nine lives" by Grant Morrison. I think he's on life seven or eight, now though.
I'm not counting the ridiculously stupid Johnny Thunderbolt creation or the current stories with the original Hourman (because he is dead, and is only around now because of a temporal anomaly).
Ma Hunkel, though, should be daid. She was old when her series debuted. Having her still around is beyond pushing it, even in terms of comic "timelines."
So, in terms of the originals, it's largely a moot argument. As far as their kids go, their ages should be closer to the ages of characters from the Silver Age era, such as Barry Allen, Hal Jordan, etc., rather than modern characters such as Kyle Rayner or Connor Hawke.
I would say, rather, time to do away with this ridiculous "sliding scale" timeline and let some people age, and maybe even die. Dick Grayson gets older but Bruce Wayne doesn't? It's just stupid.
