Anime: SAO (Hope so, may be an OVA xD)
Light novel: Volume 7 chapter 10
She won 67 consecutive 1 vs 1 duels on the street, including Kirito
and fight equal ground with Asuna.Kirito stated that her reaction speed was even higher than his and she was much more immersed into virtual reality than he was.
You can only have chance to meet her if you ever decide to read the English SAO LN which is got translating free at bakatsuki:http://goo.gl/5eDWn