The Scions are stated to have kept themselves younger with magic... though now that I say it out loud I have no idea if that's canon or headcanon that got shared a lot.

Ryne and Gaia are in their teens, Gaia may be a little older than Ryne, though. Which should put Ryne at 15-16 and Gaia at 16-17, maybe?
The twins are in the range of 16.
Minfillia... is weird, because she was a teenager in 1.0, possibly 16+, which would make her at least 20 in 2.0.
Everyone else ranges from their early 20s to... well, possibly in their 60s or more considering how some races age and their lifespans.

Do the Lorebooks give precise ages? Don't think I've seen references to that.