The 68-year-old chose a tartan coat for the occasion, and some wild accessories!
For day-two of her mum's festivities, Anne pinned a gold horse broach to her coat and threw on a bizarre brown hat, fanned with beige feathers.
Very Yankee Doodle dandy!
Zara Tindall's mother stood in her horse drawn carriage to greet the King's Troop Royal Artillery soldiers, who marked The Queen's birthday with a 41 Royal gun salute at London's Hyde Park.