 -- Princess Kate revealed today that she, like other parents, has struggled with loneliness during motherhood.

The heartfelt confession was made by Kate, the mother of 3-year-old Prince George and nearly 2-year-old Princess Charlotte, at the opening of a London school that incorporates mental health into its curriculum.

"It is lonely at times and you do feel quite isolated but actually so many other mothers are going through exactly what you are going through," Kate, 35, told two young mothers who started an app as a meeting place for young moms navigating parenthood. “It is being brave enough, like you obviously were, to reach out to those around you."

Kate, who attended the school opening with Prince William and Prince Harry, encouraged students and parents to use the support network around them because many parents are facing the same, often overwhelming issues. She also told parents that mental health awareness should begin at an early age.

"Start these conversations from a much earlier age but through play, even if their language hasn’t yet developed," Kate said.

William, Kate and Harry spent the morning discussing mental health at the Global Academy school in Hayes, near London, which also focuses on teaching students skills in the media industry. The royal trio has spent the last week in a high-profile, coordinated campaign encouraging people to open up about mental health.

Harry, 32, revealed that he had to seek counseling and nearly had a breakdown after struggling for years to cope with the tragic death of his mother, Princess Diana, in 1997.

"And then [I] started to have a few conversations and actually all of a sudden, all of this grief that I have never processed started to come to the forefront and I was like, there is actually a lot of stuff here that I need to deal with,” Harry told the U.K. Telegraph's Bryon Gordon about asking for help.

William recently disclosed that he too is still recovering from the shocking death of his mother. He also spoke of how he and Kate are raising their two young children.

"Catherine and I are clear that we want both George and Charlotte to grow up feeling able to talk about their emotions and feelings," Prince William said in an interview with Calmzine magazine.

William, Kate and Harry founded the Heads Together campaign to prioritize mental health and end the taboo and stigma around seeking help for mental health issues. Their year-long campaign culminates this weekend at the 2017 Virgin Money London Marathon in which a team of more than 700 runners are participating to raise mental health awareness.