Finally, finally I killed her.
But Jinxie is still telling me to do it. (Though right now I can't get to the Dungeon) I also don't see that as a quest in my quest log, either unfinished nor finished. So what do I do now? How do I get the next quest?

By then, Jinxie should stop popping up.
Try to see if you can go to the next zone, Ethernia in Astryl's Vale.

Hm. Okay, I have a quest in Ethernia. So far, so good. Thanks. But Jinxie is still there when I go on the World Map, I guess she didn't get the memo. *g*

She doesn't appear anymore apparently, since users during the quest complain about her blatant being-there. xD

I'll just wait, I guess. I thought maybe logout and waiting a while would do the trick, but she's still there. Still lurking with the map.

Oh, once you get the quest in Ethernia, you just do what it tells you to do. Supposed to be like

1. Finish Umbra Forest
2. Go to Ethernia, talk to NPC in the Castle (or something)
3. Go to Sweet Blossom Orchard
4. Finish quests in Sweet Blossom Orchard
5. Exit and go to Ethernia
6. Go to Astryl's Tranquility
7. Finish quests in Tranquility

Then there's a pause, where we wait for the next update. c: