It's towards the east side of the Dark Queen. Teleport to her castle, get out of it, then go east. There is a cave entrance near the mountains. There, you will find Twilight.
Confirming this does not work, at least for me. It tells me I can't leave unless I use the left door in the hallway.... which also doesn't work. I think this quest is just broken, or has to the potential to become broken somehow.
As far as I'm aware, I have a complete quest log save for returning to Roserra after defeating the Wizrd (I defeated him, but she doesn't acknowledge that), visiting Twilight, and making a potion for Yennay (no idea where to find elf ears).
This isn't normal at all. Normally, you should be able to exit the Dark Queen's castle without any problem. Have you searched through every door of it ? If yes, I am afraid your save may be broken. If that is the case, I fear you would need to restart a new game.
Yeah, unfortunately way too much of an ask with no guarantee it won't soft-lock again. Probably shelving this one until final release. Hopefully there will be a skip to new content option in a future release.
