Interesting. The source I read it in was the English translation of "Empress Alexandra Feodorovna, Her Diaries: 1917 & 1918" by Stephen R. de Angelis. I quote from the August 9, 1917 entry "Joy was bitten by a poisonous snake."
Now I'm very curious to figure out which is correct. I would think if Joy had been bitten, there would have been subsequent entries of Joy's injuries by the Empress or anecdotes by other members of the family or suite given Joy was a family pet.