Sentence:  I realized , now , that she had been showing me , in what impressed me as <WSD>being</WSD> a very accurate way , something her mother had once said to her ; it was as if she was showing me one of the reasons why she hated that woman inside her . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)