The Queen did her best to attend what she could of the four-day Platinum Jubilee celebrations over the weekend.

The royal, 96, who is marking 70 years on the throne, made an appearance on the balcony for Trooping the Colour on Thursday. However, she didn’t step out in person again after that until Sunday’s grand finale, where she surprised fans by appearing on the palace balcony once again.

“The Queen greatly enjoyed today’s Birthday Parade and Flypast but did experience some discomfort,” a spokesperson for Buckingham Palace said following Thursday’s festivities.

A source added to People that her mobility issues flared up during the course of the day.

Royal historian Robert Lacey told the magazine, “She would not want to stumble — not for her own sake but for the distress it would cause other people.”

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Bill Mott, a former Garrison Sergeant Major of London District who ran Trooping Colour for the Golden and Diamond Jubilees, said of Her Majesty not taking part in the main parade for the first time: “In all the years I did the Queen’s Birthday Parade, it was Her Majesty the Queen there. To not have Her Majesty arriving was poignant and the fact that she went out onto the balcony was lovely.

“I thought in my heart, ‘how many more times am I going to see her Majesty like that?’ It was quite sad for a lot of reasons. I know the Platinum Jubilee is meant to be a wonderful occasion and something to mark 70 years, but it was tinged with sadness for me,” Mott, who is Commandant of Cadets at Valley Forge Military Academy, continued. “It’s the end of a very powerful era. How much longer are we going to be blessed with her?”

READ MORE: Queen Elizabeth’s Platinum Party Included Tributes, Stunning Visuals

“While I may not have attended every event in person, my heart has been with you all; and I remain committed to serving you to the best of my ability, supported by my family,” the Queen said in a statement on Sunday.

The Queen has cancelled multiple engagements since being hospitalized last October for an undisclosed illness and having contracted COVID-19 in February.

She appears to be in good health, but did use a cane for the weekend’s events.