The Duchess of Cambridge played host at Buckingham Palace on Monday evening for the celebration of the 25th anniversary of a charitable organisation Place2Be. At the event, she let out an adorable detail about her youngest child Prince Louis.

Since 2013, Kate Middleton has been a patron of the charitable organisation that works towards providing emotional support to young children dealing with mental difficulties. As a part of her beloved cause, Kate has been associated with the charity and works with the pupils, children's parents and staff.

During the event at the royal palace, Kate welcomed students from New North Academy in Islington and Salusbury Primary School in north-west London. The children teamed up to perform with the musicians from the Royal Philharmonic Orchestra.

This evening The Duchess of Cambridge, Patron of @Place2Be since 2013, hosted a reception at Buckingham Palace to celebrate the charity’s incredible work over the past 25 years #25YearsOfPlace2Be pic.twitter.com/0nu0gky7Hh

— Kensington Palace (@KensingtonRoyal) March 9, 2020

According to Hello, the children sang an original song for the Duchess of Cambridge and the guests. Right before the performance, the duchess thanked the children for their performance and later wished two children happy birthday, jokingly. She then revealed it is Prince Louise's favourite song. She even said that he is "tucked up in bed."

"You've written it especially for tonight? Thank you so much! What a treat for me," Kate said.

"You taught me, right from the start, that the children in your schools are only as happy and emotionally strong as the adults in their care," the royal mother said in her speech after the performance. "That is why you take such great pride in the work you do with your teachers and your parents. You taught me the importance of creating safe and nurturing environments within schools, embracing a holistic view of emotional wellbeing which permeates through the whole school system," she added.

kate middleton
Ava Watt, aged 9 with Cystic fibrosis, presents Catherine, Duchess of Cambridge with a gift during her visit to Great Ormond Street Hospital on January 17, 2018 in London, England Getty

The event took place hours after the Commonwealth Day service at Westminster Abbey where Kate and Prince William were joined by the rest of the British royal family and Prince Harry and Meghan Markle. This was the Sussexes last royal engagement before they officially step back from their royal duties and begin their financially independent life by splitting time between the UK and North America.

Kate Middleton