This is the reason Princess Charlotte never wears trousers

(Image credit: Rex)

As you know, there are many fashion rules the royals have to follow, from Kate Middleton not wearing wedges in front of the Queen to Meghan Markle not wearing tracksuits in public.

And these rules also apply to the royal children. For instance, Prince George always wears shorts for this reason, and eagle-eyed observers have questioned whether there's a reason Princess Charlotte always wears dresses.

You might have noticed that the 3-year-old also often wears old-fashioned smock dresses with ruffles and a peter pan colour, and this is apparently so that she'll never appear 'out of date'.

Kidswear designer Rachel Riley (a favourite of Prince George's) explained to the The Telegraph: 'If they wear very simple things… it's timeless in that you can't really date a specific photo or put them in something that seems out of date. They have chosen a very traditional look and are a traditional family.'

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There are no official rules saying little girls can't wear trousers, however according to royal expert Marlene Koenig, this tradition dates back a long time.

She told, 'If you look at photos of young royal girls – from Princess Anne to Charlotte, you will notice that they tend to wear smocked dresses as little girls when they are in public with their parents.'

'If the duchess is in a dress in public and Charlotte is with her, most likely Charlotte, at this age, will be in a dress – also in formal portraits, or on the balcony for the Trooping of the Colour.I expect that when the kids are at home, playing in the nursery or in the backyard, they are wearing more casual clothes,' she added.

Penny Goldstone

Penny Goldstone is the Digital Fashion Editor at Marie Claire, covering everything from catwalk trends to royal fashion and the latest high street and Instagram must-haves.

Penny grew up in France and studied languages and law at the Sorbonne Nouvelle University in Paris before moving to the UK for her MA in multimedia journalism at Bournemouth University. She moved to the UK permanently and has never looked back (though she does go back regularly to stock up on cheese and wine).

Although she's always loved fashion - she used to create scrapbooks of her favourite trends and looks, including Sienna Miller and Kate Moss' boho phase - her first job was at, sourcing the best deals for everything from restaurants to designer sales.

However she quit after two years to follow her true passion, fashion journalism, and after many years of internships and freelance stints at magazines including Red, Cosmopolitan, Stylist and Good Housekeeping, landed her dream job as the Digital Fashion Editor at Marie Claire UK.

Her favourite part of the job is discovering new brands and meeting designers, and travelling the world to attend events and fashion shows. Seeing her first Chanel runway IRL at Paris Fashion Week was a true pinch-me moment.