Princess Kate has surprised royal watchers today by sharing photos of a private meeting at Windsor Castle.

Kate, 42, and her husband the Prince of Wales met an aspiring teenage photographer with a rare and aggressive form of cancer after inviting her to take pictures at William's Windsor Castle investiture.

The princess looked well in the two images shared by Kensington Palace on social media, wearing a maroon suit, smoky eye make up and her trademark brunette locks down.

The first image shows Kate hugging 16-year-old Liz Hatton, from Harrogate, after the royal couple met the youngster after the ceremony on Wednesday.

While the second is a group shot of the prince and princess with Liz and her family.

In a personal message on social media, William and Kate said: "A pleasure to meet with Liz at Windsor today. A talented young photographer whose creativity and strength has inspired us both. Thank you for sharing your photos and story with us. W&C."

Liz is trying to take part in as many photography experiences as possible and was invited to Windsor Castle today by William to take photos of recipients and learn about the different pictures that are taken throughout the day.

The heir to the throne found out about Liz through the London Air Ambulance Charity of which he is Patron of and held an engagement with on Monday alongside David Beckham.

Liz responded to the post on her own Instagram account, and wrote: "Such lovely, genuine and kind people, I'm over the moon that my family and I had this experience."

While William’s role in the investiture ceremony has been recorded on the court circular - a record of royal engagements - the couple’s meeting with Liz and her family was not because it was private.

Kate has been seen only a handful of times this year after battling her own cancer diagnosis.

However, since revealing last month that she had completed her course of chemotherapy she has started to return to work, conducting two meetings at Windsor Castle.

The first was on her Early Years project and the second involved planning for her annual Christmas Carol service, which she hopes to attend in December.

Kate is also expected to attend the Remembrance Sunday service at the Cenotaph on November 10.