And she was spotted with a huge smile as her youngest granddaughter, 18, appeared in the arena.
Both Sophie and Edward were seen standing as they watched the performance.
Moreover, while in the royal box, the Queen looked delighted when she was presented with a trophy, presented after her highland pony triumphed at an event earlier today.
The monarch surprised royal watchers as she arrived at the event on its second day.
The Queen looked on as Lady Louise led a parade at the Royal Windsor Horse Show
The Queen appeared in high spirits
Lady Louise Windsor made her grandmother the Queen proud today driving a carriage at the Royal Windsor Horse Show.
The young royal shares a close relationship with the Queen, spending a lot of time together and bonding over their love of horses.
Here’s all we know about Lady Louise’s close bond with the Queen.
The 96-year-old was all smiles after being driven in a Range Rover from Windsor Castle to the grounds where the show is taking place.
She remained in the front seat of the vehicle for some 45 minutes while watching an event and chatting with some of the guests.
The Queen was then driven away only to reappear in the main Castle Arena a few minutes later.
Wearing a headscarf, she made her way to her seat with the support of a light walking stick.
Sophie was spotted taking pictures during the parade
The Queen, Prince Edward and Sophie watching Lady Louise leading the parade
She opened up on the passion she shared with the Duke and their unique relationship in a BBC documentary aired last September.
Appearing on Prince Philip: The Royal Family Remembers, Lady Louise said: “The Duke of Edinburgh has been so involved in my driving which has been so lovely, although slightly scary because he invented the sport pretty much.
“It’s incredible to have learned first hand from him.”
The Queen receiving a trophy while in the royal box
Louise recalled how the Duke’s eyes “would light up” when they discussed competitions or went out practising carriage driving.
She said: “After a competition, he would always ask how it went.
“His eyes would light up because he just gets so excited when he talks about it.
“When we would go carriage driving, he would take me on a different route every day, I do not know how he managed to do that, and tell me all sorts of anecdotes about anything and everything.”
The Queen walked to her seat using a walking stick
Lady Louise performing during A Gallop Through History
In heartfelt praise, Louise added: “He is honestly one of the most interesting people I have ever met.”
Following the death of Prince Philip on April 9 last year, it was claimed Louise would inherit his latest carriage and ponies, a sign of their tight bond.
Lady Louise is also to make an appearance during one of the most anticipated events marking the Platinum Jubilee.
The young royal is among those performing during the four-night show ‘A Gallop Through History’ taking place in the grounds of Windsor Castle.
The Queen watching an event at the Royal Windsor Horse Show while staying in her car
Princess Beatrice and her husband Edoardo Mapelli Mozzi attended the charity performance on Wednesday night, while the Duke and Duchess of Gloucester were on the stands on Thursday evening.
The Wessexes will be the royal guests tonight, while on Saturday the Princess Royal will be seating in the royal box.
The Queen is reportedly hoping to make an appearance on Sunday, when most of her great-grandchildren will reportedly be featured in the show by taking part in a carriage drive.
Source: EXPRESS CO UK