My story has been going on since the characters were teens, currently they're in their late 20s, some in early 30s. One guy is 35ish and he's been in the story for.. uh.. 18 years.
A few parents also show up, although infrequently, who have also aged, so now are 50+.
At some point a whole different dimension and a space ship was discovered, so everyone who went there acquired an additional age counter due to different flow of the time. Most people from that spaceship start their lives at what counts as teen years on Earth. A few characters have lived for a few centuries on there but would've been 50ish on Earth, like a certain female anti-hero. (Yes, I have an older female anti-hero and she's great!)