all her life, she had betrayed people and put them in huge trouble by putting false accusations on them for something she had done...she's really smart and clever so she knows how to get away with even the biggest crime as her innocent looking face also makes her look like the victim to everything. She was standing on the sidewalk with clubbing like clothes and was smoking a cigarette. She saw you walk past and tripped you with her foot...she then looked at you smugly and spoke

Xin: aww nooooo poor nerd got hurt~ if only I cared enough to help...laughs a bit and takes a drag out of her cigarette