No, probably not.
Noting that Robert was in the habit of administering Elizabeth’s medicines himself, his accusers claim that towards the end of her life he increased the daily dosage of laudanum to a fatal level… And it is true that towards the end of her life, her English doctor did prescribe stronger medication to alleviate Elizabeth’s symptoms of suffocation, irregular heart action and severe coughing fits.
But why would Robert want to kill the woman he loved?
Juicy rumors always come out during the deathquicentennial, don’t you know.