Being a Duchess generally means looking perfect at all times and having a boundary between yourself and the world.
But the Duchess of Cambridge has broken down barriers by revealing she suffered a "lack of confidence" when it comes to parenting.
The royal said being a mum was tough even for someone like her who had the help of housekeepers and nannies.
"Personally, becoming a mother has been such a rewarding and wonderful experience. However, at times it has also been a huge challenge - even for me, who has support at home that most mothers do not.'
Speaking on the issue of maternal mental health, Kate, 35, was candid about how difficult it can be.
'And yet there is no rule book, no right or wrong - you just have to make it up and do the very best you can to care for your family. For many mothers, myself included, this can, at times lead to lack of confidence and feelings of ignorance.'
She continued: 'Sadly, for some mothers, this experience can be made so much harder due to challenges with their own mental health.'
While celebrity mothers such as Chrissy Teigen and Hayden Panettiere have spoken out recently about their battles with postnatal depression, the Duchess's revelation that motherhood is difficult will bring comfort to many.
"Even her!" is an expression we often hear when someone seemingly perfect has also been challenged. By speaking out about her own lack of confidence, not only is Kate demystifying the struggle but also normalising it.
What's commendable is that she's choosing to use her position both as a royal and as mother to Prince George, three, and Princess Charlotte, 22 months, to help make others feel less alone.
'If any of us caught a fever during pregnancy, we would seek advice and support from a doctor. Getting help with our mental health is no different - our children need us to look after ourselves and get the support we need.'
Kate's openness is a far cry from the stiff upper lip of old. Not only has she helped mothers around the globe, she's also brought a freshness and reliability to the monarchy in the 21st century.