Sarah Ferguson planned the perfect birthday treat for Princess Beatrice and her granddaughter Sienna

Sarah Ferguson has revealed the sweet treat she planned for Princess Beatrice's birthday and it sounds like her granddaughter Sienna had an amazing time. 

• Sarah Ferguson threw Princess Beatrice a 'fairy picnic' for her birthday and the Princess' daughter Sienna enjoyed the celebrations more than the birthday girl.
• The grandmother's plans sound magical and would make for the perfect birthday treat for children of any age. 
• In other royal news, Sarah Ferguson reveals the Royal Family’s favourite board game to play behind closed doors.

Birthdays, while a magical time for children, can often be filled with stress for parents as they buy and wrap the best new toys, prepare to host a gaggle of youngsters and entertain them with party games, and bake a showstopper cake using one of the many birthday cake recipes available online.  

Even when kids grow up, birthdays are a big deal and allow for much-needed family get-togethers where everyone can wind down and enjoy each other's company. And when Princess Beatrice turned 35 on 8 August this year, her mum Sarah Ferguson planned the perfect birthday treat for her daughter with the help of her one-year-old granddaughter, Sienna. 

During the latest episode of her podcast, Tea Talks with The Duchess and Sarah, Sarah Ferguson revealed the steps she took to set up the perfect 'fairy picnic' to delight her daughter and one-year-old granddaughter with. 

She shared, "I hid many different fairies in the garden, and I sent Sienna on a fairytale hunt to find the fairies, with wings on. She lasted with the wings on for quite a while before Beatrice and I put the wings on.  And then we had a fairy picnic once she'd found the fairies, and that was a magical day for Beatrice's birthday.

"I seriously was making Sienna understand there were fairies that are living in the oak tree in the garden so she had to go and find the little door to the fairy department store, which is the oak tree. Of course that's my next book I've just started writing about the department store with the Sluggington Smyths, which are a slug family, a very fine slug family."

Sarah, who is known as GG to her grandchildren, previously shared how she enlisted Sienna's help in preparing for Beatrice's birthday and revealed that the two of them had got 'adventurous' in the kitchen making some cupcakes for the celebrations. 

She said, "We're busy blowing up balloons and she's made loads of cupcakes. Well, she told GG [Sarah] how to make the cupcakes and then GG and Sienna had to go and try the cupcakes and then we had to put our fingers in the cupcakes, so we've been very adventurous in the kitchen, it has to be said."

The birthday celebrations brilliantly show off the truth of Fergie's previous claim that her 'childlike' behaviour helps her to be the 'best granny ever.' Speaking to HELLO! Magazine earlier this year, she revealed, "Well, the thing is, is that I’ve written 48 children’s books and I’ve flown helicopters, Budgie, the helicopter, and Little Red. And so, I’m wanting to actually write a book about a football, now.

“Hence, I’m in the room with footballs and I’m going to write about a bouncy football. But anyway, I’m probably one of the best grannies ever. The best abuela [grandmother] ever because I think like a three-year-old.”