Lady Marina Windsor is a ray of sunshine in sheer lace wedding guest dress

The British summer may be hit and miss, but Lady Marina Windsor ensured she brought her own sunshine to her friend's wedding.

The eldest daughter of the Earl and Countess of St Andrews documented the celebrations with a carousel of photos on Instagram, showing off her vibrant buttercup yellow wedding guest dress. The V-neck frock featured a button-down front, a fitted waist and a flowing midi skirt with panels of sheer lace.

Black platform heels and a matching wicker bag with embroidered flowers were Marina's chosen accessories. Beauty-wise, she wore her long hair in natural waves tucked behind her ears and kept her makeup minimal, with a flawless complexion and long lashes.

"Frank and Sas’ wedding!" Marina simply wrote in the caption alongside lots of flower emojis.

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The 31-year-old events manager was joined by her sister Lady Amelia Windsor, who chose a summery blue and red floral dress as she posed inside a marquee, shielding from the cold in a buttoned jacket.

Sustainable fashion passion

While Amelia has modelled for top fashion houses including Chanel, Dior, Bulgari, and Armani, Marina said she had no plans to forge a career in modelling, having modelled outfits designed by the late couturier Hardy Amies when she was 18.

However, they both have a shared interest in ethical and sustainable fashion. "We're best friends and are very close," Marina told HELLO!.

On her green styling credentials, the third cousin of Prince Harry and Prince William explained that she likes to shop in charity shops or borrow clothes from friends and family, including vintage pieces from her mother, Canadian historian Dr Sylvana Tomaselli.

"I think the generation above us kept their clothes so well. I'm trying to do the same thing. My mother still has some clothing in perfect condition from her twenties. I'm very lucky as she very generously lends me things. She has a great sense of style."

When she's not at formal events, Marina shows off her relaxed style on social media. She recently embraced a boho chic look in a printed skirt, pastel cardigan, and suede ankle boots during a romantic trip to Connemara, West Ireland with her boyfriend Nico Macauley.

She was pictured snuggled up to her cybersecurity worker beau as they posed on a clifftop in the beautiful County Galway landscape against the setting sun. Nico went full country chic in a Barbour jacket, shirt, and jumper.

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