Her actions will do more to implant her in a character's memory than looks.
A male character, especially in a RPG is going to see gorgeous women in every adventure. In two years he will probably have had at least one love affair and seen scores of heart stopping women.
Yes, a red haired asian girl would be memorable. But then there's that Mexican dancer who saved his life, and that English doctor that patched him up, and that French girl who broke his heart... You get the idea.
Skills are memorable. When she performed, perhaps she was clearly the best of the troop, even the best he's ever seen. Maybe she watched HIM during the performance, as if she was dancing and tumbling for HIM only. Maybe she tossed him a rose, or a silk scarf at the end of the performance, but disappeared before he could talk to her.
Alternately, maybe she wore an exotic and memorable perfume. When he passes her on the street, she seems familiar, but it's the perfume that really kicks his memory.