She highlighted their vital support for children at the end of their lives and their success in lifting spirits through laughter, fun, and play.
Kate's commendation comes as she continues to balance her public duties following cancer treatment, which was the reason for her absence from Royal Ascot.
As a royal patron of East Anglia's Children's Hospices and Ty Hafan Children's Hospice in South Wales, she emphasized the extraordinary care provided to families.
Her heartfelt message was posted on social media ahead of the end of Children's Hospice Week, an event raising awareness for these services.