He added: "My hope is that when they come back from their summer break, Meghan will be given a bit of a freer rein to express herself (within earshot of the media) and get stuck into some of the serious topics she wants to tackle. She has the soft power to help many people in this world."
MailOnline has contacted Kensington Palace for comment.
Taking on official royal engagements has been a steep learning curve for the Duchess, despite her experience in the limelight as an actress.
She's appeared visibly nervous during several events, including her first Trooping The Colour during which Harry was seen asking if she was alright on the balcony at Buckingham Palace and telling her to look up and watch the flypast.
During her inaugural foreign visit as a royal to Dublin, she found herself at the centre of debate over whether she expressed a political opinion.
Senator Catherine Noone, who met Meghan at a garden party, tweeted that the Duchess had apparently agreed with Ireland's recent referendum result in favour of legalising abortion.