She also paid a personal tribute to the "support and unique sense of humour" of her husband Prince Philip, who retired from solo public duties in 2017.
"We remember the birth of Jesus Christ whose only sanctuary was a stable in Bethlehem", she said.
In Manchester a few months later 22 people - including children - were killed when a lone suicide attacker detonated an explosive device as crowds of music fans left Manchester Arena following a performance by United States singer Ariana Grande.
The queen said in her annual broadcast to Britain and the Commonwealth that she was thinking about London and Manchester, the two English cities attacked by terrorists this year, "whose powerful identities shone through over the past 12 months, in the face of appalling attacks".
"I describe that hospital visit as a privilege because the patients I met were an example to us all, showing extraordinary bravery and resilience".
In March, a terrorist plowed his vehicle into pedestrians on London's Westminster Bridge, killing four people, before stabbing a police officer to death outside Parliament.
She said: "I don't know that anyone had invented the term 'platinum" for a 70th wedding anniversary when I was born.
Queen Elizabeth II sits at a desk in the 1844 Room at Buckingham Palace, as she records her Christmas Day broadcast to the Commonwealth at Buckingham Palace, London.More news: Uber dealt blow after European Union court classifies it as transport service
The Queen has remembered the lonely and unsafe birth of Jesus in her Christmas Day message.
"We think of our homes as places of warmth, familiarity and love", the Queen will say.
Pictures of the Queen's great grandchildren, Prince George and Princess Charlotte, can be seen, along with two wedding related images of the Queen and Philip - but taken 70 years apart.
Prince Harry and Meghan Markle have joined members of the Royal Family for the Morning Service on Christmas Day in Sandringham.
Ms Markle, who is spending Christmas at Sandringham with Harry and other senior royals, is likely to have watched the Queen's message with members of the monarchy.
The Queen left London by train last week for her Christmas stay on the Sandringham estate.