The monarch, 94, shared her joy along with the Duke of Edinburgh, Prince of Wales and ‘the entire family’ after the the couple announced they were preparing to welcome a brother or sister for their young son Archie Mountbatten-Windsor.
A Buckingham Palace spokesman said: ‘Her Majesty, Duke of Edinburgh, Prince of Wales and the entire family are delighted and wish them well.’
It is understood the Duke and Duchess of Sussex told the royal family in advance of making the news public.
Earlier tonight the couple shared their announcement by posting a candid black and white image of Prince Harry resting his hand on Meghan’s head as she lay in his lap cradling her bump underneath a tree.
The Queen led the royal family in congratulating Prince Harry and Meghan Markle after couple announced they were expecting their second child later this year
A spokesperson for Meghan and Harry said: ‘We can confirm that Archie is going to be a big brother. The Duke and Duchess of Sussex are overjoyed to be expecting their second child.’
‘The photograph of the Duke and Duchess was was taken by the couple’s longtime friend Misan Harriman. What wonderful news for the Sussexes!!’
Misan Harriman, a friend of the couple and the photographer who took the image, tweeted: ‘Meg, I was there at your wedding to witness this love story begin, and my friend, I am honoured to capture it grow. Congratulations to The Duke and Duchess of Sussex on this joyous news!’
Baby Sussex will be the Queen and the Duke of Edinburgh’s 10th or 11th great-grandchild depending on whether he or she arrives before or after Zara Tindall’s baby, which is also due in 2021.
He or she will still be eighth-in-line to the throne – and the most senior royal in the current line of succession to be born overseas.
The sex of the baby, as well as the due date, remain unclear.
The announcement came on the 37th anniversary of when Princess Diana, announced that she was pregnant with him on Valentine’s Day in 1984.
It also came just five days after the royal family celebrated the arrival of Princess Eugenie’s first child – a baby boy.
Last year baby loss charities applauded Meghan Markle for providing a ‘vital step in breaking down that stigma and shame’ around miscarriage after she revealed the ‘unbearable grief’ she suffered after losing her second baby.
The Duke and Duchess of Sussex posted a candid black and white image of Harry resting his hand on Meghan’s head
The couple, who are currently residing at their home in Los Angeles, said they were preparing to welcome a brother or sister for their young son Archie Mountbatten-Windsor
In an article written for the New York Times, the Duchess of Sussex said she lost her second child after feeling a ‘sharp cramp’ while changing her son Archie’s nappy in July at her Los Angeles home.
In her piece, called ‘The Losses We Share’, Meghan described herself tearfully watching her husband’s ‘heart break as he tried to hold the shattered pieces of mine’ while grieving for their unborn baby.
She wrote: ‘After changing his [Archie’s] diaper, I felt a sharp cramp. I dropped to the floor with him in my arms, humming a lullaby to keep us both calm, the cheerful tune a stark contrast to my sense that something was not right’.
‘I knew, as I clutched my firstborn child, that I was losing my second’.
She went on to describe how she was taken to hospital and tried to imagine ‘how we’d heal’.
The couple quit their roles as senior working royals in March 2020 in a quest for personal and financial freedom
She added: ‘Hours later, I lay in a hospital bed, holding my husband’s hand. I felt the clamminess of his palm and kissed his knuckles, wet from both our tears. Staring at the cold white walls, my eyes glazed over. I tried to imagine how we’d heal’.
The Duchess of Sussex said she wrote the article about her own loss to encourage others to talk about it.
She continued: ‘This year has brought so many of us to our breaking points,’ Meghan writes. ‘So, this Thanksgiving, ‘let us commit to asking others, ”Are you OK?”
In 2019, Prince Harry announced the arrival of their firstborn Archie to a press pool, and then later held his newborn son in his arms, with Meghan at his side, for his public debut at Windsor Castle.
The couple quit their roles as senior working royals in March 2020 in a quest for personal and financial freedom, and now live in an £11 million house in Montecito in California.