Royal fans were impressed with Harriet's look and praised her on social media.

One user wrote on Instagram: "I’ve been loving her fashion!"

Another one agreed, saying: "Harriet absolutely slays her outfits and I love it."

A third one added: "Definitely knows the right royal brands!"

A final fan said: "Modern and summery. I like it."

Peter, Princess Anne's son, debuted his new girlfriend last May during the Badminton Horse Trials.

Since then, they've made a number of appearances alongside the royals.

She even attended Royal Ascot earlier this summer, where she was seen mingling with the rest of the royals.