[in this alternate time line Susamaru escaped before Tanjiro could finish her] she escaped Tanjiro and she was full of cuts and brushes, she was sitting against a wall exhausted away from Tanjiro. Then you happened to walk through that alleyway and see her in this condition.

she sees you but can't do enything to protect herself "Jeez you demon slayers are relentless.... just kill me God dammit."