Queen Camilla is returning to public duties on Tuesday after a chest infection, although with some changes to her schedule.
The Queen, who is 77, cancelled a number of engagements a week ago after doctors advised her to rest, and missed Remembrance Sunday events at the weekend.
She will attend events in London this week but for shorter periods than originally planned.
And she will miss the premiere for upcoming film Gladiator II on Wednesday evening.
It is understood there is no cause for alarm - and her plans are being adjusted to avoid any setback after recovering from a bug.
The Queen will attend a host a reception to celebrate the authors shortlisted for this year's Booker Prize at Clarence House on Tuesday, but will meet guests for a shorter period than planned.
She will also still attend a Palace reception with the King on Wednesday to celebrate the TV and film industry, but is not expected to be present for the whole event.
The King will still attend all events, including the Gladiator II premiere, as planned.
The Queen's chest infection came just under a week after returning from a trip to Australia and Samoa with the King. The trip included a stopover in India on the way back.
Announcing the infection last week, Buckingham Palace said: "Her Majesty The Queen is currently unwell with a chest infection, for which her doctors have advised a short period of rest."
It said she had cancelled her engagements "with great regret".
The Queen previously missed a week of engagements with ill health in February 2023, when she tested positive for Covid. It was the second time she contracted the virus, having previously had it in February 2022.
It has been a difficult year for the royals' health.
King Charles received a cancer diagnosis in February. His treatment was paused during his overseas trip but was expected to begin again on his return to the UK.
Meanwhile, the Princess of Wales is gradually returning to public duties following her cancer treatment earlier this year.
She joined Prince William and other members of the Royal Family for a Remembrance concert at the Royal Albert Hall on Saturday night - her first major formal appearance since finishing chemotherapy. She also appeared at Remembrance Sunday events.
