The Queen did not attend a New Year's Day church service at Sandringham because of a "lingering heavy cold".
She also missed the Christmas Day service at her Norfolk estate and has not been seen in public for 12 days.
A Buckingham Palace spokeswoman said the Queen was "still recuperating".
She and the Duke of Edinburgh left for their Christmas break a day late on December 22, travelling by helicopter instead of train, because of colds. Prince Philip has made a full recovery.
'Up and about'
He went to the New Year's Day service alongside his son Prince Edward and other members of the Royal Family.
The Queen's absence from church on Christmas Day was the first time she had missed the service in many years.
Buckingham Palace said that was a "precautionary measure" in the cold and wet conditions and it had "no sense of undue concern".
The BBC's Richard Galpin, at the Sandringham estate, said: "We do understand she is up and about. There's no indication of there being any other serious illness involved."