Coroner Sheriff Payne told the hearing that Miss Blackman's death could not have been predicted.
He said the National Trust, which owns a stretch of the beach where the tragedy happened, appeared to be doing all it could to warn visitors of the dangers presented by the 100ft cliffs.
"Sadly, Charlotte Blackman died as a result of an accident. It was a sudden act of nature that nobody could have predicted at that time."
More top news
The West Bromwich Albion midfielder made his 633rd appearance at Arsenal.
The two bottles, dating back to 1871, were made when Queen Victoria was on the throne.
Police say there are signs of a disturbance in her bungalow which may be linked to her death.