Proper Dress Length
Every member of the royal family is always expected to be dressed properly, and the kids are no exception to this rule. While the girls are permitted to wear dresses, they are expected to be knee length or longer. In fact, you will rarely see Princess Charlotte wearing shorts or pants, though there are some occasions where that rule is bent. She will typically be seen wearing knee length skirts or dresses as well as a pair of Mary Jane shoes.
Well Mannered Behavior
As the royal children are raised knowing that they could one day occupy the throne or a role close to it, they are expected to be on their best behavior at all times. If they do act up in publicly, they are met with a serious scolding. This is why etiquette training comes in so early in their lives and the expectations are sky high from day one.