The teenager looked elegant in an all-black ensemble, which featured a subtle accessory that was incredibly meaningful.
Louise wore an equestrian brooch – a nod to her and Philip's shared passion for horse riding, in particular carriage riding, which the teenager has taken up in recent years.
VIDEO: Members of the royal family arrive for Prince Philip's funeral
The young royal had been pictured carriage driving in Windsor earlier in the week, just a few days after joining her parents at a church service.
Back in 2019, Philip was pictured proudly watching his granddaughter compete in the Private Driving Singles carriage drive during the Royal Windsor Horse Show, where she achieved third place.
Lady Louise Windsor wore an equestrian brooch - in nod to her and Prince Philip's passion for carriage riding
In an interview last May, Louise's mother, the Countess of Wessex, said of her daughter's carriage driving talents: "She is naturally so good at it, she really is. It's something that she has taken to very well."
The Duke played polo until 1971, when he discovered carriage driving, and was credited with bringing the sport to the UK.
He represented Britain in three European championships and six world championships.
Louise is a talented carriage rider
Louise was joined by her brother James Viscount Severn, 13, and the Earl and Countess of Wessex at the emotional service on Saturday, which took place at St George's Chapel in Windsor.
The teenager had been pictured out in Windsor with her mother the day before the service, where they spent time viewing some of the many floral tributes in honour of the late royal.
Due to the current restrictions amid the coronavirus pandemic, only 30 guests were in attendance at the funeral.
Those present included the Queen, Prince Charles and the Duchess of Cornwall, Princess Anne and Prince Andrew.
The young royal with her mother the Countess of Wessex and brother James Viscount Severn
The Duke and Duchess of Cambridge, Prince Harry, Peter Philips, Zara and Mike Tindall, Princess Beatrice and Edoardo Mapelli Mozzi, and Princess Eugenie and Jack Brooksbank were also in attendance.
The service was conducted by the Archbishop of Canterbury Justin Welby and the Dean of Windsor David Conner.
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