The opening of the new London headquarters for Place2Be, a children's mental health charity close to Kate's heart.
As she visited a primary school in Oxford today she was given a book of lullabies to sing to the new arrival, and a hint from an eight-year-old girl that she had no excuses not to turn in a good performance.
With the temperatures starting to rise following recent storms in the United Kingdom, she opted to wear a white coat and no tights for her school visit, where she learnt about the charity, Family Links - which provides support to pupils, parents and teachers.
A key interest for Kate, children's emotional health is prioritised at the school where teachers and parents receive help and training by Family Links. Is she the most stunning Princess the Royal family has ever seen?
The charity's new residence in Coller House, St John Street, will provide a hub for its growing research and evaluation teams, and will be used as a site to train counsellors, teachers and school leaders in therapeutic care and emotional support for pupils. "It's extraordinary actually", she said.
Kate replies, to which the fortune teller says, "Indeed he will".
Emelia Robertshaw, 11, Jodie Brackett, 11, and Zhara Gathenya, 10, spoke to her about life at the school.
Jodie explained that the children have discussions at school during Circle Time so that they can open up.
"Soon you will meet a handsome man, a rich gentleman", the student playing the teller can be heard saying.
The duchess was dressed in a Marlene maternity cocktail dress by Seraphine, an outfit she wore during a recent visit to Norway with William.
"Having watched that again now, you just sort of think, my God, that's quite odd, isn't it?" he continued.
Emelia, whose sister has met the Duke of Cambridge, said she was practising what she would say before meeting Kate.
Royal sources say the duchess will remain busy for the rest of March but plans to slow down her official duties next month.