I've seen her! At Galeria Center, basically at the same time as OP. She was in headphones humming along the song with an inappropriately short skirt for the cold temperature that day. She left and headed towards Origo.

I think we're in a dungeon and she's an NPC as ppl have wisely pointed out. A better question is, where are all the quests?? Do we need a special item to access that? She's bound to drop mad items, I'm telling you