The monarch (96) is attending the military law of the Loyalty Parade in Edinburgh.
When she waved to royal fans, the Queen appeared to glow purple for her engagement on Tuesday.
The head of state, facing ongoing mobility issues, had her cane.
The Queen joins the army at the Palace of Holyroodhouse this morning, marking the Platinum Jubilee in Scotland.
A parade and presentation of the keys to Edinburgh Castle will take place in the gardens of the palace.
The Army, Navy, and Air Force are represented by the army, and when the Queen arrives in the garden, a royal salute is performed.
Sir Lyon of the King of Arms then introduces the Queen to the three senior representatives of the service.
They will be joined by three cadets representing each service, who will parade the keys of Edinburgh Castle across the garden before presenting it to Maj. Gen. Alastair Bruce of Klionaihi, the governor of Edinburgh Castle.
The Major then addresses the Queen.
Loyalty and key presentation to Edinburgh Castle marks the 200th anniversary of George IV’s visit to Scotland in 1822.
It was after the Queen arrived in Scotland yesterday and had a week of royal engagement with other members of the royal family.
She attended a historic key ceremony at the Palace of Holyroodhouse, the capital of Scotland, with the addition of Prince Edward and Prince Sophie, known as the Earl of Forfar, north of the border.
This event is the traditional opening round of Holyrood Week for royalty who have traveled to Scotland all at once.
The Queen, wearing a light blue coat and hat, was symbolically provided with the key to the city by Lord Provost of Edinburgh, Robert Aldridge.
Tradition stipulates that the monarchs will return them and entrust their custody to elected officials of the city.
Prince Charles and Princess Anne, known as Count Rothesay, north of the border will also be engaged in Scotland this week.
Princess Royal will conduct an investigation on behalf of the Queen at the Palace of Holyroodhouse later today.
On Wednesday, Prince of Wales, Edward, Sophie, and Anne will be welcoming guests at the Palace of Holyroodhouse Garden Party in honor of their active contributions to communities throughout Scotland.
On Thursday, you’ll see Charles attending the Queen’s bodyguard in the Scottish Redend Parade in the gardens of the palace.
The successor to the throne and Anne will also participate in the Thistle Service at St Giles’ Cathedral.
Edward will be hosting a celebration on Friday in the gardens of the Palace of Holyroodhouse, which won the Edinburgh Gold Award from all over Scotland.
The Palace of Holyroodhouse is the official residence of the Queen of Scotland, at the end of the Royal Mile in Edinburgh.
Details to follow