The Narnian world has one universal language and no linguistic drift. It is bizarre. (What's even funnier is that the universal language is English -- no joke! my crowning proof is the carved inscription in Harfang, wherein the letter E in 'UNDER ME' is an actual capital letter E. I blame that state of affairs on Digory. If he hadn't jumped into the pool right as Aslan was creating Narnia, Aslan might have picked a different language, but Digory, Polly, Uncle Andrew, Frank, and Jadis did show up, so Aslan went with what was already to hand, so to speak. *grin*)

I have always been convinced there was some connection between Jadis and the Lady, but I was never certain what it might be. This theory is the most personally amusing to me, and I think it explains the Lady's connections to the northern giants, why she waited to invade Narnia, and why she tried to invade so indirectly. (She was trying to avoid Jadis's mistakes, you see.)