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The post contained two photos: one of the Queen mid-address, and one of the Royal Standard flag flying in the wind.
"Her Majesty’s words touched my core and inspired us to never give up," Ferguson wrote in the post. "To unite as we have before. To never forget the British humour and to remember... We should take comfort that while we may have more still to endure, better days will return: we will be with our friends again; we will be with our families again; we will meet again."
Widely known as "Fergie," Ferguson previously has spoken about coronavirus, explaining on Twitter that she understood coronavirus to be a warning from Mother Nature.
Hours before Ferguson's former brother-in-law Prince Charles was revealed to be COVID-19 positive, she said the world should have seen the current pandemic coming.
In her messages, Ferguson called attention to Mother Nature's previous warnings.
"Mother Nature has sent us to our rooms.. like the spoilt children we are. She gave us time and she gave us warnings. She was so patient with us. She gave us fire and floods, she tried to warn us but in the end she took back control," Ferguson wrote along with a photo of a yard and trees in bloom.
The Duchess of York's second tweet added a glimmer of hope as she asked her Twitter followers for answers.
"She has sent us to our rooms and when she is finished clearing up our mess. She will let us out to play again. How will we use this time? xxxx."
Fox News' Melissa Roberto contributed to this report