She is a bit beside herself.她有点忘乎所以了。

固定表达beside oneself with表示的是，（因高兴或愤怒而）忘乎所以、得意忘形、飘飘然而不能自禁之类的心理状态和行为举止。
　　再如，
　　He was beside himself with excitement when he was told that he had been admitted by Beijing University.
　　当人们告诉他已被北京大学录取时，他兴奋不已。