Theres no solid answer. Even jiwoo is not to sure of her age lol remember him panicking when he found out that the stronger they are, the slower they age? but assuming they graduated at 18 (koreans typically end high school at that age) and he’s been training with kayden for like a year by then, they probably met when jiwoo was 17. Everyone kept saying that jiyoung took her post at a young age, and people were also telling jisuk to take over instead, im just guessing that her age gap with jisuk is not too far maybe 3-5 years ish. So 17 & 20-22 ish maybe. Considering jiwoo is around 19 now jiyoung is probably 22-24. If you’re thinking about the age gap based on their education, it’s iffy. But if you’re thinking about it based on their positions in the awakened world, they’re quite equal.

for my peace of mind, what is the age gap between jiwoo and the noona? Also what age did he meet her
I’m trying to wrap my head around how this relationship is okay and not predatory because apparently a lot of people like them. (I haven’t read this since like chap 300+)