In a letter to child development experts, Catherine, the Duchess of Cambridge, outlined some of the difficulties new parents experience after welcoming their children into the world.

The comments from the former Kate Middleton came as her husband, Prince William, Duke of Cambridge, opened up about his own struggles with mental health in a BBC documentary.

The duchess said she appreciated the “sense of isolation” new parents face, writing: “I can understand that people are nervous about asking for help for fear of judgment, and how that sense of isolation can quickly become overriding and debilitating for any new parent,” reported Sky News.

“Recognizing that the task of parenting is substantial, I have realized the importance of working to make it easier for parents to request support.”

The duchess sent the letter to a steering group she set up last year to compile research on early child development. Praising the experts’ work, she said she would continue to promote the health and happiness of families and children.

She wrote, per Harper’s Bazaar: “Over the past few years, I have had the privilege of speaking with mothers and fathers about the issues they deal with day-to-day. Your work has affirmed to me just how important it is to listen to parents and those who care for children… I hope my long-term commitment to working in the early years will help make a difference over a generational timescale.”

On Monday, the duchess unveiled a multisensory garden at the annual Chelsea Flower Show in London. The woodland wilderness, which is intended to promote children’s well-being, includes a rope swing, a campfire and a stream. According to the BBC, the Cambridge children—Prince George, Princess Charlotte and Prince Louise—helped gather twigs and moss for the garden.

Catherine told the BBC: “I really feel that nature and being interactive outdoors has huge benefits on our physical and mental well-being, particularly for young children.

“I really hope this woodland that we have created inspires families, kids and communities to get outside, enjoy nature and the outdoors, and spend quality time together.”

The duchess visited the garden with her children and husband over the weekend, before returning with a group of schoolchildren Monday. She worked on the garden with landscape architects Andree Davies, Adam White and the Royal Horticultural Society.

William detailed his own struggles with mental health in a BBC One documentary called A Royal Team Talk: Tackling Mental Health. In the film, which aired Sunday, the duke discussed the difficulties he experienced after his mother’s death in 1997.

Describing “pain like no other pain,” he said his own bereavement had helped him connect with families experiencing trauma when he worked as an air ambulance pilot.

Although the “British stiff upper lip thing” has its place, we need “to relax a little bit and be able to talk about our emotions because we’re not robots,” he said.