Becca, 22, is performing the role of Games Maker.

She said: "When I first heard I was chosen to be a Games Maker at the Olympic shooting events in London's Royal Artillery Barracks I'll admit I was a little disappointed.

"I didn't even realise it was an Olympic sport. However, since starting my shifts I've seen how skilled the athletes really are.

"I've been present at three finals and medal ceremonies so far. I've mingled and worked with people from all over the world and been spotted on TV by my mum several times.

"I've even been within touching distance of a gold medal for the Men's Skeet.

"On Wednesday I had the honour of holding the Olympic Torch. It has been an amazing, once-in-a-lifetime experience."

Her 25-year-old sister is dancing at the Paralympics Opening Ceremony on August 29.

She was offered the chance to dance the samba in the closing ceremony of the main Olympics, but had to turn it down due to time pressures.

She is sworn to secrecy about the theme but hinted "it's very British".

She is very excited about upcoming rehearsals in the main stadium. She will be one of 10,000 participants at the opening of the Paralympics.

Suzy and Becca are the daughters of Michael and Jane Tobias.

Suzy works for Iris, the advertising company which designed the two Olympic characters Wenlock and Mandeville, while Becca is about to enter her honours year at Glasgow Caledonian University, reading events management.