Britain's Prince William and Kate Duchess of Cambridge and Prince George. Picture: Reuters

The Duchess of Cambridge became the latest member of the royal family to highlight mental health issues, admitting that being a new mother can be a struggle.

"It is lonely at times – you do feel quite isolated," said Kate, mother to Prince George, three, and 11-month-old Princess Charlotte.

She also urged parents to start teaching children about emotions before they can even talk, saying it is "essential" to encourage "good mental health" at a young age through play.

She was speaking at a public engagement with her husband, Prince William, and brother-in-law, Prince Harry, to open a new academy school in West London.

The duchess wore a chic crimson suit with a flattering ruched jacket from the Armani Collezioni line, costing £544 (about R8 700). She paired it with simple nude Rupert Sanderson heels and a matching clutch bag.

The visit follows five days of campaigning by the young royals on the issue of mental health, with Prince Harry speaking of how he had sought professional help after coming close to a breakdown over his mother’s death, and William disclosing he still feels the shock of Diana’s loss.

Talking to Katie Massie-Taylor and Sarah Hesz, co-founders of an app for new mothers, Kate suggested parents should have "age-appropriate conversations… bringing in the topic of mental health".

She said: "It’s the same with younger children, and helping parents to start these conversations from a much earlier age, but through play, even if their language hasn’t yet developed.

"Very young children actually don’t even have the language to express how they’re feeling, so it comes out in behavioural problems. So being able to find ways to address those problems really early on is great."

Kate has mentioned the difficulties of motherhood several times before, suggesting she may be speaking from personal experience.

Last month she admitted being a parent had been a "huge challenge – even for me who has support at home that most mothers do not".

Prince William told students at the new Global Academy: "The strongest guys are the ones who can talk about [mental health]. The weak guys… bottle it away."

Daily Mail