Nicole Brown Simpson’s sister has relived the horror of their mum breaking the news she had been slaughtered to her young children. Dominique Brown, 59, said their mother Juditha told Nicole’s daughter Sydney, then eight, and son Justin, then aged five, about how Nicole had been knifed to death in 1994 outside her home in Los Angeles – with her late ex-husband OJ Simpson later sensationally cleared of the murder in court. She told People about the horrific moment: “She goes (to Nicole’s kids), ‘Mommy’s in heaven.’” Dominique added in the devastating wake of Nicole’s murder, she threw herself i…