In Blue Kingdom you are asked to find 6 out of 18 Correspondence Sigils.
After gathering 6 (which is pretty easy) you can no longer find more, even after turning the quest in.
My question is - is there a way to meet quest giver later and maybe get an option to find all 18 Sigils?
No–once you have the six sigils, you just turn them in and end the quest. IIRC there’s a nice payout in terms on xp, but that’s the end of it.
Update: You can, in fact, meet the quest giver later, exactly where she says she’s headed. There is no reward for this other than text. Then you can go back to the BK and see her there, too. It doesn’t have to make sense. There doesn’t seem to be a way to collect all the sigils–once you have six, you’re locked out of continuing the quest.