Princess Kate has a close-knit band of friends and family who will be helping her through her battle with cancer, after she confirmed her diagnosis via video message last Friday.

One of these will be her younger sister Pippa Middleton, one of Kate’s most trusted confidantes who is also a mother to three young children – the cousins of Prince George, Princess Charlotte and Prince Louis.

The Times reported that Kate and Pippa even enjoyed a secret skiing holiday in Méribel with their husbands and children, which was kept under wraps.

The publication wrote: “They managed to keep their holiday secret for a few days of fun with their husbands and young children: cosy après-ski lunches together hidden in the snowy forest.” Kensington Palace has refused to comment on the story.

A source close to Pippa said: “The three siblings are incredibly tight … Pippa not only as a sister but as a best friend she can confide in. They are extremely loyal to one another.”

Pippa was also maid of honour for Kate for her wedding to William at Westminster Abbey on April 29 2011, with them both wearing Sarah Burton for Alexander McQueen.

In May 2017, Pippa married her husband James Matthews at St Mark’s Church at the Englefield estate in Berkshire, with Kate and William and their young family in attendance.

Mr Matthews is the heir to the lairdship of Glen Affric in Scotland, meaning Pippa will one day be known as Lady Glen Affric once her husband inherits.