to 1906 and a royal stay at Abergeldie Castle in Aberdeenshire, Scotland. Queen Mary, who was a princess and young mother at the time of these photos, dressed in a marvelous flowered and plumed hat for play in the garden with her children.
Embed from Getty Images
Embed from Getty Images
Photo from Getty as indicated
Royal Hats 
Abergeldie Castle, which is in close proximity to Balmoral and Birkhall, has a fascinating history which is detailed in a Wikipedia article here:
https://en.wikipedia.org/wiki/Abergeldie_Castle
Originally built in 1550, it was leased by Prince Albert in 1848 and appears to have been very popular among the royal family through the early 1900s, being used regularly by the then Prince of Wales as well as his sisters Princesses Louise, Victoria and Maud of Wales.
I enjoy seeing photos of Queen Mary as a young mother, as she always seems so dour in photos of her later in life. Trickymum, love your description of her putting the basket of flowers on her head!
Here’s a rather uncharacteristic photo of Mary, taken the same day perhaps?
Embed from Getty Images
Perfect for playing with the children!
It is actually a lovely example of an Edwardian hat, and good to see Mary before she adopted her endless toques.
That’s what I call a real cartwheel hat! Looks like she picked up a basket of flowers, stuck a feather in and put it on her head.