The Princess of Wales has been named as the new patron of Tŷ Hafan.
Catherine visited the children's hospice in Sully on Thursday to meet children, families and staff providing palliative care.
Earlier this month, she announced she was in remission from cancer and making a phased return to her royal duties.
The late Princess Diana previously served as Tŷ Hafan's patron from 1995 until her death, while fundraising took place to build Wales' first children's hospice.
King Charles III took over the patronage in 2001, two years after it opened.
Irfon Rees, chief executive of Tŷ Hafan, said: "We are deeply honoured that Her Royal Highness The Princess of Wales has become Patron of Tŷ Hafan and it was an absolute pleasure to welcome Her Royal Highness to our hospice for the first time today."
"As our patron, Her Royal Highness will be an inspiration for children with life-shortening conditions and their families, our dedicated staff and volunteers and everyone who so generously supports us."
"No parent ever imagines that their child’s life will be short. Sadly this is the reality facing thousands of families in Wales. We can’t stop this happening, but together we can make sure that no one lives their child’s short life alone."
The Princess of Wales was seen talking and playing with different children, and had her hand painted by 9-year-old Lottie, whose sibling is being treated at the hospice.
The wellbeing of children and their families has been close to Catherine, whose first patronage as a member of the Royal Family was the East Anglia Children's Hospice, where she maintains a close relationship to this day.
Tŷ Hafan says the Princess is looking forward to building a similar relationship with not only the hospice, but the children and families it serves in Wales.