article_snippet: The girls' mother told police that The parents often locked her 11-year-old sister up when The girls' mother misbehaved .
article_snippet: Authorities also said The girls' mother had discovered the siblings having sex in 2011.
article_snippet: The girls' mother reported to police that The girls' mother heard noises coming from the bedroom and found the teenage boy having sex with the teenage boy sister, who is a year younger.
article_snippet: The girls' mother told police that The girls' mother separated the siblings and asked the siblings what happened.
article_snippet: The girls' mother told The girls' mother that The girls' mother did not want to 'do it' with The girls' mother brother but her brother put pressure on The girls' mother.
article_snippet: The girls' mother also referenced the earlier abuse by The girls' mother .
article_snippet: The girls' mother parents had also removed The girls' mother from school, documents show.
highlights_snippet: In 2011, the brother and sister were discovered having sex by the brother and sister mother .
  