Ironically, Vilma will find a candle that she casts light on and then tosses it into the hallway, lighting it up for Flair.

Sure enough, 5' to the north is the wall (no window) that is the end of that extension as the outside of the manor is on the other side.

Where Vilma dropped the candle is right next to a door to the west.

The candle's light shines south into the darkness another door to the west 20' down from the nearer.

Immediately to Flair's south, it seems there is a washbasin and faucet.