Well . . . wait, wait. Might they be referring to scars left by the lightning rather than the face scar? Because then it makes more sense. Still more likely to leave him thinking of family betrayal, but more potential for, say, a thoughtful caress during a shippy scene with Katara.

Snorting fire at random intervals, possibly muttering deranged ramblings under her breath, but with severe control. Walking like a clockwork doll, bending like a living diagram. She seeks perfection at the cost of, well, not being wacky races.