Darren Guilbert commented: "Hope she gets better. Big hugs.”
Marian Brooks added: “Hope she makes a quick recovery.”
Elizabeth Feetham simply put: “Get well soon Your Majesty.”
On Thursday, the palace said the Queen would attend Sunday’s service, and had previously said it was her “firm intention” to be there.
The monarch, who lived through the Second World War as a teenager, is head of the armed forces and attaches great importance to the poignant service and to commemorating the sacrifices made by fallen servicemen and women.
On Sunday morning, less than two hours before the service in Whitehall, Buckingham Palace said: “The Queen, having sprained her back, has decided this morning with great regret that she will not be able to attend today’s Remembrance Sunday Service at the Cenotaph.
“Her Majesty is disappointed that she will miss the service.”
Heir to the throne Charles placed a wreath of poppies on his mother’s behalf, as has been the tradition since 2017, but the act had further symbolism given her absence.
In what would have been the Queen’s place on the balcony stood her 86-year-old cousin the Duke of Kent, with his sister Princess Alexandra at his side, as they solemnly watched the proceedings.
The Duke of Cambridge, Earl of Wessex and Princess Royal also laid wreaths at the memorial.