The Greyhawk languages exist, and having them might provide a clue or two, but they will mostly serve as window dressing. Common is still the language spoken in most lands, and this adventure will take place almost entirely within the Maure Castle dungeons.
Speaking of light sources... would it be ok to add an everburning torch to Celine's equipment? It certainly makes sense to have some permanent source of light (not only the spell).
Oh, and for the record, yes, Celine is going to continue with concentrating on the spell, of course, to be able to discern the aura strength and school of magic and so on (what Detect Magic allows).
I will give Brisarion and Silhouette a couple actions first and then I will post the results of your detect magic. If they do not answer soon, I will assume they are waiting for your to get the results of your spell.