I think Nancy was telling the truth about what she knew, but drew some erroneous conclusions about what happened to JonBenet based on her (Nancy's) own experiences. She believed JonBenet was murdered by the same people who had abused her (Nancy) sexually. IMO the same people may be involved, indeed Nancy and JonBenet both knew the White family, but I don't think the murder is as simple as it would appear on the surface if you agree with this theory. For one thing, JonBenet was never raped nor is there physical evidence of sexual assault or abuse other than the injuries inflicted at the time of her death.