Royal expert and founder of Royal Musings blog, Marlene Koenig told Hello Magazine that all young royal girls have only worn dresses out in public, so they have a "clean, traditional look".
She said: "If you look at photos of young royal girls – from Princess Anne to Princess Charlotte, you will notice that they tend to wear smocked dresses as little girls when they are in public with their parents – getting dressed up in a clean, traditional look."
However, this does not mean that Charlotte is not allowed to wear trousers, but instead, wears dresses to follow royal formalities - which is why Kate is often also seen wearing dresses.
Ms Koenig added: "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, on the balcony for the Trooping of the Colour.Click link for blog for full post from EXPRESS.