Speculation and rumour are not what's needed now but what the internet excels at. Thankfully they're having an inquest but as davek rightfully points out, it's not really in the public domain, it's a private matter.
This isn't a suspicious death. The inquest is as much for the family. The police have said they do not believe anyone else involved.
Therefore the ins and outs of family relationships in the case are not in the public interest. Had this been a murder, a suspicious death, and a potential victim of crime or a matter of public safety it would be a different matter.
But its not. And people shouldn't treat this like a murder trial. Its an inquest. Its only about determining cause of death.