Kate beams at annual Scout ceremony alongside television star Bear Grylls

Kate, 31, beamed after being greeted at the National Review of Queen’s Scouts at the royal castle in Berkshire by Chief Scout, adventurer and television star Bear Grylls yesterday.

Around 400 youngsters and their families from across the UK and around the Commonwealth flocked to the prestigious annual celebration.

Pregnant Kate hid her growing baby bump by donning a light green Mulberry coat.

Despite being around six months pregnant, the royal is increasing her charitable workload and is now patron of seven organisations as well as being a volunteer with the Scout Association.

Grylls – who became the UK’s youngest Chief Scout in 2009 aged 34 – said Kate was an “incredible role model” who helped show that Scouting was not just for boys.

Since Kate joined the Scouts last year, more than 2,800 new adult volunteers have joined up – the second biggest rise since 1986.

Grylls said: “The Duchess is an incredible role model and she helps us show that Scouting’s not just for boys.

“She’s also such a generous volunteer and everyone is so excited to have her in the Scouting family.”

He added: “Many people have followed her lead and are getting involved and enjoying the adventure.”

Last year, the Queen – who was celebrating her 87th birthday privately yesterday – honoured Scouts at Windsor.

Most of the youngsters at the special event received Queen’s Scouts awards – the highest a Scout can gain – for achievements including carrying out regular community service for a year.

Kate also had the chance to meet several young people who received gallantry awards after being nominated for their bravery and heroism in their everyday lives.

The annual celebration at Windsor Castle dates back 80 years.