i could not have told the random lady that shapeshifters don't exist. the absence of evidence is not the evidence of absence. however, if she is afraid of shapeshifters, well, i know i'm not a shapeshifter, but i can not 100% prove that to her. similarly, she knows she's not a shapeshifter, but she cannot prove to me that she is not. therefore, rather than living in fear that everyone could be a shapeshifter, once again, there is no guarantee that they must be evil. there can be good shapeshifters, so she should not fret. there are also bad people as well as good people, but she still interacts with society (including me). why should shapeshifters be any different?