Sentence:  Not unnaturally, "Auntie" took this communication in bad part. Thus outraged, she showed herself to be a bold as well as a furious virago. Next day she found her way to their lodgings and tried to recover her ward by the hair of the head. Then, <WSD>thwarted</WSD>, the wretched creature went to the police for help; she was versed in the law, and had perhaps spared no pains to keep on good terms with the local constabulary. 
Meaning of the word marked with <WSD> tags:  To cause to fail; to frustrate, to prevent.