Sarah Ferguson has revealed her grandchildren have granted her new book, Flora and Fern: Wonder in the Woods, the young royal seal of approval.

The book is the first in a new series by Prince Andrew's ex-wife, who, as a best-selling author, has published more than 70 books.

The Dychess of York, 65, has published many children's books such as 'Budgie the Little Helicopter', and 'Her Heart for a Compass' for adults.

Flora and Fern: Wonder in the Woods has been illustrated by Denise Hughes, with a second book set to follow next year.

As grandmother to Princess Beatrice's three-year-old daughter Sienna, and Princess Eugenie's two boys, three-year-old August and one-year-old Ernest, Sarah said that she strives to share the book's ethos - which is "the power of community and being connected to the world around you" with her own grandchildren.

Sarah - who also acts as grandmother figure to Beatrice's eight-year-old stepson, Wolfie - is set to welcome another grandchild into the world next year after Beatrice shared news of her second pregnancy earlier this month.

Speaking of her grandchildren, Sarah told HELLO!: "August reads Wonder in the Woods every night and I read to Sienna, August and Ernie as much as I can. Reading is a way to spend time together, especially at Christmas."

Discussing the power of reading, she added: "Reading is one of the main reasons I love writing children's books.

"We need to encourage literacy; 30 per cent of five-year-olds are falling behind expected reading levels and one in three disadvantaged children cannot read or write at the expected level for 11-year-olds."

She added that Sienna, August and Ernest also serve as inspiration for her books, telling the publication: "The idea for a festive story came from coming together with my grandchildren and children to celebrate important milestones and times of year."

After news of Beatrice's second pregnancy was revealed, Sarah took to Instagram to share her delight at being set to welcome another grandchild next year.

Alongside some pictures of her children and grandchildren, Sarah wrote: "A very proud GiGi/Mum today. Such an incredible blessing and an embrace to my heart.

"Wolfie, August, Ernie and Sienna will be over the moon to have the fifth member of the five aside!"