I don't doubt your mother heard this but, as boring as it may be, I think Valentino died a natural death. As soon as he was hospitalized, there were rumors that he was only there to publicize Son of the Sheik or that he had been shot by a jealous lover or the husband of one of his lovers. I wouldn't doubt that most of these rumors were started by hospital workers. The latter rumor especially fit nicely into his image of a "Latin Lover" - loved by women, loathed by men. All that might be believable too if Valentino has simply dropped dead one day. The fact of the matter was he complained of abdominal pain and indigestion in the weeks before he died.
Valentino was basically surrounded by people who took advantage of his celebrity and cashed in like mad on his death. His manager and Adolph Zukor collected life insurance policies after he died but neither bothered to buy him funeral plot. The manager also hired Italian fascists to "guard" Valentino's body while he lay in state for publicity. I don't think he or Zukor would have passed up an opportunity to cash in on the nuttery that would have arisen had Valentino been murdered.
I don't think his family would have stayed silent for decades either.
I suppose a conspiracy is possible but what would be the point? Who would benefit from that lie and why would it be hidden? By the time Valentino died, Hollywood was already known as a "sinful" and "immoral" place because of the numerous other scandals including William Desmond Taylor's murder so why would they hide Valentino's? I don't think the real story needs any jazzing up. It's sad enough already because Valentino likely would have lived if the doctors would have operated sooner and antibiotics were around.

Yes maybe someone really killed the Sheik.

Hmm. Interesting. I wouldn't rule it out. Look at the story behind the movie "The Cat's Meow", for example. Some people believe that director Thomas Ince was accidentally killed by William Randolph Heart, but it was so long ago and it might have been covered up.
I suppose we'll never know, but there are so many Hollywood conspiracies, so it's fair game.
Who wants to live forever?

You probably never will because it was a BIG cover up, everybody related to it is now dead and the only reason I know what I know is because my mother happened to be in the hospital when this happened. I wonder though, why none of the nurses (and their offspring) haven't mentioned this.
Odd no?

sounds intresting,but never heard of it.