Members of the Royal Family have been supporting the Queen throughout the mourning period, with some expected to visit her at Windsor Castle on her special day tomorrow.
The Queen's birthday on Wednesday falls within the two-week period of royal mourning, which is being observed until Friday.
No photograph to mark the milestone is expected to be released tomorrow.
The pandemic meant the Queen's official birthday celebration known as Trooping the Colour, normally staged in June, has been cancelled for a second year running.
Last summer, an event dubbed "mini Trooping" was staged at Windsor Castle, and Buckingham Palace has said options for an "alternative parade" were being considered at the Queen's Berkshire home.
Meanwhile, the Queen has suffered further heartbreak following the death of her close friend Sir Michael Oswald on the day of Prince Philip's funeral.
Her Majesty's trusted racing adviser passed away from a long illness on April 17 aged 86.
Sir Michael looked after the Queen and Queen Mother's racing interests for almost 30 years.
He was regularly pictured next to the royal at racing events over the years.
It comes after news that the Royals have agreed on a rota to visit as the monarch grieves the death of Prince Philip.
Princess Anne and Sophie Wessex were reported to be among the Queen's first visitors ahead of her 95th birthday on Wednesday.
Her Majesty will also be visited by her son Andrew, granddaughter Eugenie and her newborn son August in the coming days, the Mirror reported.
The plan to support the Queen is said to have been formed by the female leading figures in the family, including her daughter Princess Anne, daughters-in-law the Duchess of Cornwall and the Countess of Wessex, supported by the Duchess of Cambridge.
Philip's family and friends gathered at St George's Chapel at Windsor on Saturday to say their final farewell to the duke who died peacefully on April 9, aged 99.
His death came a few months short of his 100th birthday, which was due to be the focus of royal celebrations this year while the Queen's 95th was to be more low-key.
After 73 years of married life, the Queen reigns alone without the support of her "strength and stay", as she famously described her late husband.
The Queen, like the rest of the nation, has spent much of the past 12 months in lockdown but has also experienced issues within her family.
The fallout from the Duke and Duchess of Sussex's decision in January 2020 to step down as senior royals was still being felt in March that year when the country went into the first lockdown.
Harry and Meghan's recent Oprah Winfrey interview plunged the monarchy into another crisis when they made accusations of racism within the family and a lack of support for Meghan's mental health.
The involvement of Prince Harry, if any, in the plan is uncertain but it’s thought he could stay in the country for his grandmother’s birthday after leaving his return flight to Los Angeles open.
The Duke of Sussex, 36, jetted into Heathrow eight days ago and self-isolated at Frogmore Cottage in Home Park at Windsor before he was cleared to attend Saturday’s funeral.
Prince Harry held talks with William and Charles after the pair asked to meet him together so that words could not be misconstrued, a royal insider has said.
The face-to-face meeting was held on the grounds of Windsor Castle following the service for the Duke of Edinburgh over the weekend.