Sarah Ferguson today paid tribute to her 'dear friend' the late Queen on what would have been her birthday - but royal fans were quick to spot a blunder in her message.

The Duchess of York, who was married to Queen Elizabeth II's son Prince Andrew between 1986 and 1996, was a good friend of the late monarch, who died in September 2022.

Fergie shared a smiling picture of the late Queen in an Instagram post, but fans were quick to point out a simple mistake that she made in her accompanying tribute.

The duchess, 64, wrote: 'Today we are remembering Her Late Majesty Queen Elizabeth II on what would have been her 97th birthday. 

'Thank you for all that you have taught us, for being a steadfast leader and dear friend. You are sorely missed.'

Sarah Ferguson today paid tribute to her 'dear friend' the late Queen on what would have been her birthday - but royal fans were quick to spot a blunder in her message

Queen Elizabeth II was born on April 21 1926, which means today would have been her 98th birthday, rather than her 97th - as Fergie had written.

One person said: 'She would have been 98. My dad was born same year, 1926.'

Another added: '1926 to 2024 should be 98.'

However, others came out in defence of the duchess, insisting it was a typo.

One woman said: 'To all those correcting Sarah Ferguson, I'm sure she knows exactly how old HM Queen Elizabeth would have been. It can only be a typo.'

Sarah was known to have had a close relationship with the late Queen even after she divorced Prince Andrew in 1996 after a decade of marriage.

She has previously described the late monarch as her 'total idol'. 

It comes after the duchess thanked a fan for their 'cherished' support in a heartwarming hand-written note following her cancer diagnosis.

Fergie shared a smiling picture of the late Queen in an Instagram post, but fans were quick to point out a simple mistake that she made in her accompanying tribute

It comes after the duchess thanked a fan for their 'cherished' support in a heartwarming hand-written note following her cancer diagnosis 

The Duchess of York replied to a message of support with an adorably illustrated card featuring corgis wearing crowns, dog collars and beds, as well as bones and tennis balls 

The Duchess of York replied to a message of support with an adorably illustrated card featuring corgis wearing crowns, dog collars and beds, as well as bones and tennis balls.

It also included a photo of Prince Andrew's ex-wife lying in the grass with the late Queen Elizabeth's royal pups - which she has been taking care of.

Instagram account @theroyalmailbox, which shares their correspondence with royals and socialites, posted a photo of the exchange. 

'I received this lovely reply from Sarah, Duchess of York, regarding her cancer diagnosis,' the caption read. 'This card is double-sided.' 

The card was sent on February 3, and the poster received their reply on April 11. 

The sweet message comes as the Royal Family has faced a bout of health issues, with Sarah, King Charles III and the Princess of Wales all undergoing cancer treatment. 

Sarah was herself diagnosed with skin cancer just months after having a mastectomy for breast cancer. Pictured last month 

Sarah was known to have had a close relationship with the late Queen even after she divorced Prince Andrew in 1996 after a decade of marriage

In January, the Duchess revealed that she was diagnosed with skin cancer just months after having a mastectomy for breast cancer.

Last month, the mother of Princess Beatrice and Eugenie said she is 'full of admiration' for Kate Middleton for revealing her diagnosis. 

Taking to social media, Prince Andrew's ex-wife, fondly known as Fergie, payed tribute to the mother-of-three, saying that 'everyone is praying for her'.

Sarah Ferguson has previously described the late monarch as her 'total idol'

In a heartfelt Instagram statement, the Duchess said: 'All my thoughts and prayers are with the Princess of Wales as she starts her treatment. 

'I know she will be surrounded by the love of her family and everyone is praying for the best outcome.

'As someone who has faced their own battles with cancer in recent months, I am full of admiration for the way she has spoken publicly about her diagnosis.'