RiderFan said: Yukari is still a child compared to the ages of some of the other characters such as Suwako, Kanako, Shinki, Eirin, Yuuka, Keine(?) etc...
Nobody actually knows for sure how old she really is. Only that she's, in fact, older than Gensokyo itself.
Chen:"Ran-shama?" Ran:"Yes Chen?" Chen:"If Yukari-shama end up disappointed with these cosmetics she's gonna beat us again, isn't she?" Ran:"I'm afraid so."
The sealing was recent, but Gensokyo itself is much older.
Whenever Yukari's age is mentioned, it's said she's at least 1200, older than the history of Gensokyo. However, this likely means the beginning of Gensokyo's recorded history, begun with the first of the Hieda. So both are older than that.
Yukari befriended Yuyuko 1000 years ago. Before that she was warring with the Lunarians. That she had not only the power, but advanced motive, resources, and influence to do so then, it likely means she had been around some time before. Around this time she was already a major force, if not totally made one by the war.
No one introduced comes close to Eirin, that's for sure. I'd put Yukari at 3000. That's around the same age as Suwako and Kanako, if not slightly older. Then Yuuka at 2000. I don't think Keine is that old, but there's been no real hints either. Probably anywhere from 1000-1500. I think that's all fair.
